So the psychic warrior and soul knife look... fine? They do their job well. I won't get into them. I want to discuss the psionic wizard (psion henceforth).
Its sooooo close, and yet...
It first reminded me of the original UA Eberron article with artificer as a subclass of wizard. It barely scraped the faintest hint of what made the full class great and smeared it on the classic magic-user class. Obviously, its a much better sub than that original artificer one, but it had a similar feel to that. Or did it?
The psionic character class has had many iterations in D&D, but the closest to a a standardized form would be the 3.x psion class: power points, power levels, Int caster. He felt like a psionic wizard. A quick rundown of his powers showed some classic wizard powers ported over either wholesale (identify, daze, knock) or similar enough to be effectively the same (energy ball, incarnate, remove viewing). Complete Psion shortened the gap further, leaving very little daylight between the psion list and the wizard list.
And yet, giving psionics over to wizards doesn't completely jive either. Sure, a psion and a wizard filled a lot of the same roles, but they weren't 1:1. For example, psion powers were known like a sorcerer, wizards kept them in a spellbook. Having psionics needing spellbooks doesn't feel right. Further, there are some spells that don't feel right for a psion (specifically, summoning and necromancy) while some powers clearly in the psionic wheel-well (such as healing) aren't there.
And then there is power points/psionic strength points; probably the only design element consistent through 4 editions was using a mana/point system rather than slots. It kinda feels like a betrayal to not be counting points when using psionics.
Personally, I think the best bet is to make psion a class that is similar to the wizard BUT separate. Not the re-invention that the mystic tried, but something that takes the wizard, lobs off the spellbook, replaces spell slots with "power" (spell) points, customizes the spell list, makes the subclass features part of the the base class (along with some good ideas stolen from the mystic) and then adds a couple "disciplines" (telepath, kineticist, nomad, seer, and shaper) as subclasses as its own. It can repurpose most of the spells from the PHB, add some new ones, and then bring to a boil.
Its not the easy drop-in subclass, but its not the complicated mess that the mystic was. Its fairly close to what Mearls was wanting. Its probably the best. Because its balanced on paper and works fine enough if you're looking to make a kalshatar wizard, but it just doesn't feel psionicy enough to be the "psion" class of 5e.
That said, its better than nothing and I'll adapt if this is all it is. But they are so close...