I have both BB:CSII (Not Extend) and SFxT and I have opinions on both that you should in no way listen to.
Firstly: As for balance, SFxT feels balanced to me, characters have strengths and weaknesses, such as Hugo getting to, like, 800 dmg (avg about 500) also he’s a slow character and lack mobilty etc.
BlazBlue i’d say is just about as balanced, but i believe it has a Very High barrier to entry.
Alot of move notations, quick fast combos, blocking, Barrier blocking, jumping barrier blocking, emergency wakeup, wakeup rolling (back, forwards), mid-air wakeup.
Characters like Lambda-11 just make you frustrated.
2: BB:CSE has access to about 16 characters (give or take 1 or 2) but they are all very unique and have unique mechanics:
Examples: Arakune - Teleportation, invisiblity, Curse Mechanic: Build the curse on opponent and when full, unleash bugs from all angles of the screen.
Carl Clover - Control 1 main character and a secondary character at the same time!
Iron Tager - Grappler, Magnetism Mechanic: Build up Magnetism and then pull your opponent towards you.
Although SFxT has more characters (30 ish?), and they allow for greater variation within the confines of this game. but not as weird and strange per character as BB.
3: I live in the UK, SFxT seems to be fine right now, still new.
BB:CSII (i think we share with BB:CSE) is a little light in the endless lobby, although i expect you’ll always get an online match in ranked expect to meet the same people repeatedly.
4:I’d say they both allow for creativity. SFxT is probably better for new combos as it’s new and tech hasnt been discovered, BlazBlue has been out a long time so it’s generally been thoroughly explored, give or take the latest patch.
**The most important thing to note, is that BlazBlue:CSII (at least) doesnt use shortcuts like SSF4 &SFxT. **
Example. 2xqcf PPP - in SSF4 it’s lenient on your inputs, if say, you miss a down.
BlazBlue seems to be designed for arcade sticks, if your inputs are not exact it wont come out. (Messes me up often).