I'm hopeful you'll give 5e at least a perusal so you have a reason to stick around.
Having read every iteration of the public playtest (and giving lots of feedback) and having run 3 different one-offs throughout the process, I feel pretty confident I know the system from top to bottom to feel disinclined toward playing it. I may not know the exact specs of a few stray PC build feats in the live iteration, but I'm more than comfortable in my assessments.
I generally like Exhaustion. I like the idea of Concentration (its buff-stacking limitation is good in terms of execution). I love Background Traits. I love Legendary creatures and Lair Actions.
However, there is just far too much that I don't like that is absolutely embedded; core conceits, principles, and techniques that underwrite how an expectant play session should manifest. And that is a cleaned up AD&D + a few slightly modernized bells and whistles + PF archetypes + 3.x save paradigm/multiclassing + bounded accuracy (which makes martial classes underperform compared to their AD&D counterparts). One that relies on an AD&D ethos and principles (GM force and lots of interpretive rulings of martial/mundane action declarations) to produce the default play experience.
And don't get me wrong. I feel very, very confident that this is 100 % design intent. To that end, I feel that they did a great job. They produced a game that appeals to the OSR crowd, the 2e AD&D crowd that just wanted a modernized 2e rather than 3.x, the PF crowd, and the 4e crowd that liked the deep PC building rules (mostly players) but wasn't wedded to the the very distinct system components and the ethos/techniques of the system that made it what it was (certain GMs - like me). Is that big tent enough to pass muster? An exercise for the player-base I suppose.
In what other situations is the fighter going to have an advantage?
Also, I don't see why a 20th level fighter shouldn't be a serious threat to a large army on his/her own. Aragorn, Gimli and Legolas clearly thought that they would pose a serious threat to a small force of orcs, and they probably weren't 20th level fighters in D&D terms.
I would prefer this as a methodology if it applied to casters also. So the caster simply has the INT-based, trained only skill "Create fire magic" and the GM decides what is reasonable or unreasonable for that skill to accomplish.
1) This is what I was getting at above in response to TwoSix. The implications of bounded accuracy on martial heroes is profound. This system wants to be modernized AD&D, but AD&D fighters would shred legions of canon fodder far, far, far, far before level 20. They would outclass armies (on their own) due to their ridiculous AC vs to hit, HPs, ridiculous saves, ridiculous attacks per round and either the Heroic Fray rules or the 1 attack/level versus said infantry that you would outclass. Army. Decimator. Gone from this edition.
2) I still want to know why the player fiat of Background Traits (
available at 1st level to all characters and my favorite part of the system!...one that is oddly at tension with the design ethos of 5e) can't be extended to later on in the same way that Paragon Paths and Epic Destinies are? Why can't Fighters get traits at (say 11 and 17) that give them an extension of (with enhanced potency of course) the 1st level fiat power from Background Traits? What is so "gone rogue" about that? Stuff like:
Destined Scion - Get supernatural-like (not magic) stuff (Beowulf etc) to do supernatural things on whatever schedule.
Leader of Men - Men-at-arms flock to you, or you have gathered them, to carry your standard and fight for you. The standing force (army, what-have-you) legitimate, codified functionality in action resolution.
Warrior of Legend - Your presence moralizes/mobilizes layfolk, gives your enemy peers pause, and causes their forces to shrink (literally and figuratively) and/or abandon cause. Again, codified, legitimized fiat. Like Background Traits. Not GM whim or discretion.
Those things would provide players of Fighters with legitimate means to comparably (with respect to Wizards) affect the trajectory of noncombat conflict resolution. It would do so with tech that is already in the system (Background Traits) and it would play to archetype.
Repeatedly interfacing with a bounded accuracy task resolution system (and inevitably failing repeatedly), subject to GM will/inclination/interpretation won't do the job (at all).