This sounds similar to the way that Humanity has you choose cultures every Era, with the option to stay the same culture at the transition, as opposed to the way Civilization plays it, where you pick one culture (and leader) at the beginning and stick with it throughout.
I've been thinking of something in that wheelhouse, but a sort of 2e/4e mash-up. Four classes (Warrior, Mage, Priest, and Rogue) that get a completely fungible slot progression, and 0-9 level powers split up into domains. Each class gets a default domain (Warrior - Defend, Mage - Control, Priest - Motivate, Rogue - Strike), and two elective domains (two class domains for humans, a class and a kindred domain for others). You'd pick up new domains at roughly the same rate that a 5e character gets feats.
I don't want to hijack the Mearls thread, but to respond briefly, the way I am working it right now your first choice (of the four basic classes) does do a lot to basically define your character, each path adds to or modifies that - but as currently built you have to choose a path when you get to the requisite level, you cannot, for example, just stay a Warrior at 3rd level and not choose one of the four paths. One thing I am considering doing is making sure each basic class has one choice that is a "simple" path that hues close to the standard archetype.
I don't agree about feats (other then the known problematic ones), but I do agree with Multiclassing.
I have no idea how feats hurt the game....at least you get something more than +1 to a stat's bonus. Boring.
Mr Mearls. In response to your free article on 5e DCs, I have to say. The obvious conclusion is that at level 1, the typical DC should be 12.
Which is indeed what we see in most published 5e adventures, monster ACs, spell save DCs et al.
