FORM WALL OF TEXT!!!
That being said, during the playtest I found a lot of people/comments/circumstances where excluding people/styles they didn't like was more important than positive support for what they wanted.
The attitudes of the edition war were still going strong through the playtest, and not all of the negatives, nor many of the misconceptions of that unfortunate era are entirely gone, either.
Case in point...
I find the fast pace of 5e combats more exciting
That's fine. It'd be nice if it were more tunable without extensive modules and house rules adding to the rules to put back in options and interest. One of the quiet failures of 5e is that it too often went with opt-in rather than opt-out, and make up from whole cloth rather than ban. I guess it was a matter of limited resources and wanting the base game to be reminiscent of the limited explicit options of the classic game. I can see the positives of the approach: Making the new edition familiar and attractive to long-time and returning players of the older editions; saving design resources; re-emphasizing story over content to avoid bloat; and establishing the need for a DM willing to make rulings and add/mod rules to undercut player empowerment and RAW obsession and bring back DM Empowerment as a community zietgiest, not just a written policy (like Rule 0).
than the drawn out slog that many combats in 4e became as people counted out squares in different combinations, looked over pages of powers, counted effect squares, interrupted with reactions and so on.
None of those things actually contributed to a combat being a 'drawn out slog' and none of them were absent in the editions immediately prior to or following 4e. The main difference was that any class could avail themselves of the range of options implied by those 'problems' - movement/range/area/positioning mattered to everyone, not just to casters tossing AES; in-play choice of defined, dependable, high-impact options was available to everyone, not just casters; off-turn actions mattered to everyone, not just those casting an immediate-action spell. The same was true out of combat, 4e's systems tended to involve everyone. Involving everyone does lead to slower overall play, and longer waits for your turn than marginalizing players based on choice of character concept in combat or exploration and/or those who are less assertive in RP situations.
It's not, IMHO, too high a price to pay for greater engagement and inclusion at the table. If you are engaged or entertained by other players' turns, at all, it's not even really a price, at all.
5e, BTW, though it does return to the unfortunate tendency of marginalizing some player choices in combat, does compensate for the phenomenon by offering fewer such choices, and making them numerically effective (reprising 2e's partial solution to the problem), and it hasn't turned the clock back much out of combat. Backgrounds give even marginalized classes some potential to have a plausible role out of combat, and Bounded Accuracy lets anyone chime in with a check that might get lucky in almost any situation.
5e moves at a pretty good pace for me and my group, the combats are fun and we get much more done outside of combat in a comparable time frame than we did with 4e.
5e calls for about twice as many encounters as 4e and has no formal structure that can be adapted to the full range of non-combat challenges. So, yes, there's a potential - if you tend towards the 5MWD and have fewer combats than expected, and speed up out-of-combat resolution by focusing on specialists' contributions - to 'get more done' and for the players getting that more done to enjoy more play time than others.
Whether that's good depends upon the dynamics of the group. Some groups do have wallflowers who would rather avoid the spotlight, and are OK getting in just a fraction of the participation and glory that more assertive players hanker for. Other groups are relatively uniform in their levels of assertiveness, system mastery, and interest (or lack thereof) in playing concepts that happen to map to top-Tier classes (some even have that magical combination of system-masters interested in tweaking out low/mid-Tier classes and casuals playing unintentionally nerfed top-Tier ones).
Because it wasn't boring, trivial, or over too fast like 5E tends to be.
If it's boring or trivial, can it really be over too fast? 5e requires 6-8 encounters (typically combats, it doesn't have much in the way of non-combat 'encounter' structure or guidelines) per day, with 2-3 short rests, to maintain balance among it's resource-differentiated classes (it's less an issue if you have nothing but neo-Vancian casters, or nothing but BMs, Monks & Warlocks, or nothing but Champions & Thieves/Assassins). It doesn't have the huge amounts of between-combat healing that 4e had or 3.x/PF has, so it's a matter of attrition, not individual-encounter-challenge, and many of those combats will have to be 'trivial.' Getting them over with quickly (or even spending more play time avoiding them) only makes sense.
The problem is there in the mechanics either way. Some people being naive or choosing to ignore it doesn't make it not there.
Yes, there are potential problems in the mechanics. There's also less of a culture of sticking to the mechanics no matter what, and actual encouragement to just overrule the mechanics whenever they're less than ideal.
I disagree, epic level math never worked - even after MM3.
Epic worked as neatly as Heroic & Paragon - though PCs could take on more/bigger challenges over the course of the day. So it could get a little too easy if you didn't keep ratcheting up the scope as you changed Tiers.
And perception that PCs fell behind the math curve initially was only true for some. If you had group synergy (which I contend was 4e's greatest strength and design intent), then there wasn't a math problem. No to mention the damage that could be done at all times was just crazy huge and completely destroyed the game math if you were not prepared for it.
Simply having a leader could compensate for that initial perceived 'Math' problem, as did the ever more potent crits of high level characters (might be the damage potential you're talking about). There were some crazy high-damage exploits here and there, but the pre-essentials ones (like the Fey Charger, for instance) were all 'updated' away.
I too think 5e monsters need some work, but I generally find it easier to do than 4e (unless it is a straight up reskin). Though, 5e is probably easier for me because of all the work I did to change monsters in 4e.
I rarely ran an unmodified monster in 4e, because the off-line tool, balky as it was, made modding them very easy, and I could just print out the actual monsters I was using. Very convenient. Absent the tools, re-skinning and less extensive on-the-fly mods were the easier way to go. And they were very easy. I don't mod 5e monsters - not proactively, anyway - CR guidelines aren't dependable for placing or designing monsters, so it's more expedient, and, again, very easy, to keep them behind the screen and mod/fudge on the fly to make each combat come out just right.
For 5e I have actually created my own Monster Design by CR table for monsters CR11-50. In my table I increased AC, DC, Attack bonus, & DPR to keep my monsters around longer/make them more deadly (I've got a thread in the homebrew forum if your interested). After playing some more at higher levels in 5e I am looking at increase HP as well by adding elites, and solos like 4e (already tested some in my home game).
That seems like a substantial mod. I can see modding 5e to get where you want though, even if where you want is also pretty close to 4e, as it's always easier to work with the current edition, especially compared to an edition with virtually no support (as opposed, say to 3.x, which has PF & other 3pp support via the OGL/SRD, or classic eds, which have OSR material to lift from). You have a more vibrant community to spark off of and an easier time finding interested players.
Also, I haven't much of an issue with creating long, feature rich battles (we typically do 3-4 combats a day).
That sounds good. What did you do to get there? 'Tactical' module, I assume, but what else?
I haven't seen the same issue with using a large number of lower CR monsters that you are experiencing.
I can't imagine how you avoid it without fudging (which is perfectly legit) or creating a novel mechanic to consolidate them. Bounded Accuracy's effects seem inescapable. Unless the gap is just huge, and PCs have absolute maximum ACs compared to less-than-CR 1 monsters, I suppose.
My PCs can handle as many as I am able to throw at them (and by that I mean as many monsters as I can reliably manage as a DM), the same as 4e.
How many is that? I don't suppose it's hundreds? If you ever do want to handle a really large battle, adapting swarm style rules to large groups of humanoids - 3e and 4e both did it - can let you have hundreds or even thousands of enemies in a battle, and it side-steps the problem of Bounded Accuracy and large numbers. (If a unit of archers just pounds a beaten zone for save:1/2 piercing damage, or a pike hedge just makes one attack per enemy at a higher bonus & damage than one of it's individual members, for instance, all the BA and logistical issues with large numbers of enemies vanish.)
When a max optimized player in 4e, at high epic, can do something like 900hp nova damage (I think the highest I've seen was something over 1,100), then it doesn't really make make much difference what I do tactically (not entirely true - but I think you get my point)
Builds like that are more theoretical than practical, though (and, again, the pre-essentials ones often got properly updated with extreme prejudice). The gold standard for an optimized striker was taking a Standard, not a solo, in 1 round. You could intentionally run a one-off with a character like that, but in the last 3rd of an actual campaign you're not going to see it.
The issue i had was mostly with "solos" which really should not have been run as solos.
If you were dealing with known-broken builds and unaware of the updates that fixed them, I'm not surprised. Demolishing a solo in one round was the kind of thing that got a build nerfed hard.
I overcame these issues. I designed more tactically engaging encounters, developed more system mastery, and revised monsters. However, that was a lot of work, that eventually made playing less fun.
Sounds like you did it the hard way. One nice thing about 5e is that it sets us up to do things the easy way, but creating that expectation of DM rulings before everything. Present a broken build based on an obviously bogus interpretation, and arguing 'RAW' won't get you anywhere. ;>
For me (as DM), a decent fight leaves about a third to half of the PCs near death, dead, or dying. Maybe this was easy for you in 4e, but with all the healing options in 4e it took me about 2 years of playing about 1/ month to get to a point to where I could consistently design "decent" combats.
I believe 5e calls that 'Deadly.'

I guess it's like 'decent' in that it starts with 'D.' In 4e, fights were often challenging enough - standard encounters vs ordinary characters, harder vs optimized ones - to /drop/ individual PCs in the course of the fight, but ending a battle with multiple PCs dead/dying was aiming pretty far beyond the expected mark in either 4e or 5e (or 2e, out of lower levels, for that matter). I'm surprised you didn't stick with 3.x or go PF.
That randomness I'm coming to discover is a result of Bounded Accuracy endeavoring to keep the probability of success around 50%
Closer to 65% for PC attack rolls, typically, IMX. Saves are entirely another matter. Checks are often even easier. 5e isn't shy about throwing out DC 10s.
combined with fewer rolls to resolve a given activity and few or expensive means to mitigate randomness.
There is one big, unlimited way to mitigate randomness: not calling for rolls. I'm not just talking about not calling for checks, but also not rolling damage, or rolling dice behind the screen strictly as a 'placebo.' I know those aren't solutions you can implement, as a player, but they are solutions your DM can use, if he shares your perception of the issue.
I'm finding this to be an even bigger problem than the combat randomness. You really don't feel good at anything, and it doesn't help that at my table the DM generally uses DC 15 as the default difficulty, which on any given character means that about 90% of the time for any randomly selected skill the chance of success is 50% or less. It also doesn't help that most tasks that involve skills tend to involve only a single roll.
Those are DM decisions that'll have that effect, they're not strictly speaking "5e's fault," - aside, of course, for empowering DMs in the first place. With higher DCs, proficiency, and especially expertise, are more important, specialists will tend to step forward for a specific skill and others to not participate, much as in 3e. That /does/ give you an opportunity to define your character and powergame a little by maxxing a skill here or there.
First is that because 5E combat is designed to go fast, PCs don't have the staying power they did in 4E and non-rocket-tag 3E, or even higher level AD&D. Monsters need to be able to threaten the PCs somewhat in a 2-3 round fight. The second is that party composition varies wildly. A party that has a Wizard with Fireball ready to go is far better able to handle a mob of Orcs than one that lacks any AoE.
But what party lacks any kind of AoE? Every full caster has 'em even Bards.
5E kind of forces you to tailor encounters specifically to the party if you want any sort of climatic end battle, and that's assuming the party gets there in one piece.
If you want a specific feel to that challenge, sure. But that's always been the case.
This kind of goes back to having to tailor encounters to the party, which you really didn't have to do at all in 4E and I think 4E was better for it.
/IF/ a party covered all 4 roles, and wasn't overly optimized, sure, but I've run for plenty of 'aberrant' parties that required some customization - either to challenge, or to avoid overly brutalizing. Sometimes that's just an on-the-fly adjustment to tactics, though. Using 'bad tactics' in a party that lacks a Defender & Controller, for instance.
Maybe it's a feature of the level range I've been playing at--I'm typically looking at ~4 players at low to mid level. 4E had 30 levels, and I ran dynamic encounters at levels 6-10 I don't feel like I could run at the same levels in 5th edition, where there are only 20 levels (and while I appreciate the offer of a table for CRs 11-50, it wouldn't help for those reasons).
5e combats aren't meant to be dynamic, just fast.
But I honestly don't see how you don't see the number gap in monsters. The baseline of the system takes it into account--in 4E, an encounter of moderate difficulty was considered one same-level monster for each PC. In 5E, a moderate encounter is around one same-CR monster for a party of four (not quite, but it's pretty close).
Yes, 5e CR is more like 3.x CR, that way. The assumption is the party having numeric superiority. It's an important assumption, due to both Bounded Accuracy, and the fast combat mandate. A single monster means the DM has one 'turn' and it's shorter. Fast combat isn't just about spending less time in combat, overall (or 5e wouldn't have twice as many combats/day recommended), it's about cycling turns faster,
particularly the turns of the monster(s) and the lower-agency (and, ironically, more DPR-focused) classes.
Also in 5E, once you reach the point where there are five or more monsters on the board, a single Fireball or other AoE is likely to instantly kill a good number of them, at least up to level 10 or so. As you scale down CR, it becomes very apparent--two CR 4 creatures are considered a moderate challenge for four level 7 PCs, while in 4E, you could have up to
nine level 6 monsters before the encounter pops over on the side of "deadly".
the problem in 5E typically becomes that hordes of smaller monsters tend to be much more deadly if you don't have a good Area-of-Effect spell ready, and if you do, they tend to be trivial. There's not much in the way of middle ground there. That's the experience I have had, anyway.
Your experience fits what the numbers indicate. It's probably intentional. Even in 4e, remember, 'minion sweeping' was a Controller (Wizard/full-caster) contribution. Minions were just, ironically in spite of technically having 1 hp, more durable vs AEs than lower-level monsters are in 5e.
I realize it's not a thing exclusive to 5E, but I am finding it much more challenging to work "behind the scenes" in 5E than I did in 4E, where I did most of my DMing. I'd agree that 4E required significantly less "tailoring" than 5E does, and in my book, that makes it more flexible, because you can run all sorts of challenges without worrying so much whether or not the group has a fair shot at it.
What do you mean by "behind the scenes?" If find that 5e works very well if you take much of the resolution behind the screen, while 4e worked well above-board - I assume that's not what you were referring to.