Just played C-Wara yesterday (many days ago) and this is what I observed.
2B, 5C, j.B, j.C - Seem to have either more hitstun and hitstop or faster startup (sans 2B on startup and his multi-hit moves seem to have more hitstun/hitstop in general)
5B - Bigger hitbox; much easier to juggle and guardbreak (air unblock, not guard crash).
j.A - Either smaller hitbox or shorter active frames.
j.B - In certain situations, cancelling into j.C will get you all the j.C hits. Before, you would fall too low pretty much all of the time.
j.C - Improved by quite a bit. First of all, you can more or less cannonball it now! Second, since I THINK there is more hitstun/stop it is also much easier than before to combo this into another j.C afterwards. Yeah, you don't even have to time it anymore because it's braindead easy now to do j.C, dj.C.
Cannonball a j.C and hitconfirm into another j.C? Easy. Heck, sometimes you can aerial hit j.C low to the ground, land, 5b j.A j.C dj.C.
236A/B - Either faster or bigger hitbox. Still need confirmation on this one.
22A/B - Hits noticeably higher and executes more quickly.
421A/B/C (teleports) - Startup is faster now so a slimmer chance of getting CH2 in the face whenever you feel like using it.
j.236A/B/EX - Yeah, this is the new monster that, along with his other buffs, make him feel just that much more playable. They all have fairly quick startup. The real selling point though, is that they all have HUGE hitboxes which makes them a real beast of aerial attacks. A version hits a moderate-sized square right below his waist. B version is a bit slower but hits a huge horizontal rectangle at about the same height as A version. EX version I haven't tried out enough, but on hit it produces the same wallslam as the ground 236C does and lets you combo after it. Both A and B version are very safe on block but fucks you up if whiffed above their head.
The different versions also affect Wara's aerial momentum differently from each other. A version retains horizontal momentum while B version freezes wara but retains vertical momentum (so if you were jumping up you'd continue popping up and eventually land). EX version drops you to the ground after execution. Can't do anything until you hit the ground after claws.
j.22A/B/C - New awkward air dash. Basically, these inputs will make Wara airdash in specific angles. A is 30 degrees downwards, B is straight ahead, and C is 30 degrees upwards. Of course, they don't actually interact with the regular airdash so it's possible for him to airdash twice (all his command airdashes go forward only... too bad).
623C - A bit less recovery now I think.
236C - Less invincibility. Only invincible around the superflash now and wears off quickly afterwards
MBAA C-Warakia's a real beast, at least compared to before.
Edit 3: Revised and added information.