I think personally that you are underestimating the crappiness of the old system. It was awful to be blunt. Every single item had to be designed to a standard which made it acceptable regardless of whether it was given out in a treasure parcel or enchanted from pocket change by a much higher level PC.
I think this is a bit like what Winston Churchill said about democracy - "It's the worst system of government there is - apart from all the others we have tried from time to time..." The old system was/is clunky and restrictive, sure - but the new is worse, from my perspective. As for standards of acceptability in design, I think that
should still apply. A broken rules element is a broken rules element, regardless whether the base rules make it a freely accessible player resource or a perk to be awarded at the DM's whim, as far as I can see.
Time and time again we saw where that lead as basically all the interesting items were nerfed to uselessness.
If the rarity system is an excuse to feed overpowered items into play as "DM awards" that is far worse, to my mind. And if it isn't then the same constraints on design will need to apply.
I think there are already two good avenues for this sort of "cool/powerful" element, actually - consumable items (which have IMO been sadly ignored and poorly dealt with by the rules so far) and Artefacts (a much underrated and underused classification, I think, no longer restricted to higher levels).
Beyond that some items will ALWAYS be stronger than others for a given build.
Agreed. One of the things I don't think was well thought through at the get-go was the scope and role of items in the game. It still seems way too "all things to all men" and fuzzy. Functions of items basically fall into four categories:
1) The 'key bonuses' to ToHit, AC, NADs and (to a lesser degree) Damage.
2) Other fixed bonuses to damage, skills, etc.
3) 'Power' abilities that allow some special function to be used, generally as an action option, by the wielding/wearing character. Generally restricted to Encounter or Daily use.
4) 'Special' modifiers like giving damage done a keyword/type, giving light, giving movement modifiers or options.
Of these, I think (1) is a bit too much like a "feat tax" and should not be there - just give an extra +1 to each per three levels as fixed bonuses and remove the 'Expertise' etc. feats' plusses. (2) need to be very carefully controlled by bonus type (i.e. make them all 'Item' bonuses to block the "superstacking" builds). (3) are interesting and fine, but need to be controlled so that the character powers remain the core of the character, not a huge set of item powers; this might work for Superheroes games (the "gadget hero") but not for plain D&D. Limiting it to one item power per encounter (kind of similar to Channel Divinity) might work, here. Finally, (4) could probably be mostly left unrestricted - or maybe a few might need to feed into the "one item schtick per encounter" system along with the (3) category.
Your statement about balancing them being difficult is apt, but you should have said "flat out impossible" not very difficult. This means with crafting/purchase in the hands of the players we see simply endless repetitions of Iron Armbands of Power, blech!
I actually don't think it would be impossible - but it would take so much person-time to retool all existing items (for no return) that I don't see it being in the least viable.
If the alternative to players buying/making items is for IAoP to be a perk for DMs to give out at whim for "good" behaviour (as defined by the DM, of course) - blech!
While the tracking of daily uses wasn't TOO onerous it is still another thing to track and I'm glad it is gone. Beyond that explaining how the rule worked was a royal pain in the ass. Players got confused between the character's daily use allocation and daily uses of individual items, etc. I don't know how many times I've explained this rule to some players before they 'got it'. When they did get it they universally hated it. I have yet to ever run into a player that liked this rule.
There are plenty of rules players dislike, but rules are there to give a good, balanced, fun game, not what players think is their "due". Sure, some folk found it confusing as written, but when we started using glass beads to represent "item uses" (alongside those we use for healing surges and action points) just about all that confusion went away.
It made weaker daily item powers absolutely useless as well.
Less use
ful, certainly - but that begs the question why they are daily powers to begin with. I think it goes back to what I said above about 'scope and role' of items. Maybe I could say it better as "creation rules" - there need to be clearer ground rules about what items can and can't do; guidelines similar to those evident for class powers and (kinda) for feats.