The SoCal group actually really enjoyed XII, we obviously liked it and along with the UK bunch were the few groups that promoted videos of us playing when it out in the arcades. Don't forget we also had the machine at my place for a bit and CMD.Duc (Ash) and myself played a lot on the console the first 2 weeks and Duc even hit #1 if I'm not mistaken. I don't want ppl to think that we only play(ed) XIII.
I really liked the charge CDs into crumple, I don't see why they can't keep that going in future KOFs; it just adds a little more mind games to the current mechanics. As much as I like s.C, CD, DM I think it wouldn't translate as well as it forced only certain DMs (basically DMs that could "chase" the opponent after the DM) to take advantage of the system and wouldn't work for XIII.
The CC system worked well but it was kinda like a double edge sword. At low-level to mid-level matches it helped even the playing field. However as time progressed at higher level matches it felt kinda like how "Max Guard Canceling" worked in '95.
In KOF'95, as long as you were completely MAXed, you could cancel your block frames into a special (and I think even a DM). Using Rugal as an example, you could time it so that you block by doing qcb, hold back (hit occurs), immediately do ub+K and it'll perform his Genocide Cutter (qcb~ub+K). If you basically perfected that system, it was kinda dull and nobody would want to attack and it rewarded turtling more. From a balancing standpoint, certain characters has huge advantages depending on the motion of their specials.
CC isn't as bad, but if you play ppl like Mr. Kof or Reynald (which IMO he was better at XII than he is at XIII, and course he's not shabby at XIII at all). It was scary to stick anything out against them as they never hesistated to CC you. This diminished the zoning game greatly, and ultimately made the game feel different.
Finally, the online play really killed the charge CD attacks as anyone could see it coming a mile away due to lag.
EDIT: Just re-read my post and I hope it didn't come off a negative, I do like XII =)