Having the basic framework is good, but knowing how and when to deviate from it could have made the game better. Each role and each power source should have something that connects them so that it is identifiable that they are related. I feel like roles should have connections in effects (they can do similar kinds of things) whereas power sources should have connections in builds or causes (they go about things in similar ways even though the effects are different). 4e has a little bit of that with Channel Divinity for Divine classes and power points for Psionic classes, but not all of the sources are quite so clear cut and there are exceptions (see Runepriest and Monk). Something should tie the Fighter, Rogue, and Warlord together all as Martial characters, the Bard, Sorcerer, and Wizard together as Arcane characters, and the Barbarian, Druid, and Warden together as Primal characters.

Possibilities:
Martial: martial weapons, stances (usually 1 from class and 1 from subclass), maneuvers with points in place of regular encounter powers (maybe like 5e Battlemaster fighters)
Divine: channel divinity, domains
Arcane: Spell preparation, fewer at will, more daily, metamagic