What part of the controls was bad, exactly? I don't really think they're bad. I was always using a Classic Controller though, so maybe that's it?
The game used the following controls on CController:
Left Stick = move
Right Stick = jump
L Button = block
B button = normal attack
(Hold A) + B = charged attack (where you would hold A for a while and press B, and depending on how long you held it, various specials would happen)
R Button = dodge (combine with a Left Stick direction for a directional dodge)
A+B = Finisher (when the combo bar is filled enough)
X = Super Finisher (combo bar filled to max) <--- the evil game-breaking move, though it really wasn't that bad as long as you knew how to block
L+B = Guard Breaker
Y = Sub-Weapon
B+Y = Object Action (depending on character, it would place a juggle-generating bomb on an object, or would chuck the object somehow to the opponent).
Remember that 'modding' can also mod these actions. If you could improve the control scheme, how would you do so?
Would you perhaps assign Jump to a button, and control the jump direction with the L button?
Maybe you would assign directional dodges directly to the right analog stick? Hmm...