Not if you remap them properly. I remapped all the controls for each version of SC to match each other, and now I prefer the Gamecube the most. It makes for the easiest combos using X + A, X + Y, and Y + A.

Lousy B combos, but I never used those much anyhow, unless I was doing a throw. And I have the throw combos mapped to the shoulder buttons. CAKE.

Most are not overpowered, mostly they only give slight framerate or recovery advantage and some are near useless. SCIV is a lot more technical than what you see at face value, frame data is everything in this game at the higher level, which is why a lot of SC2 veteran hate the online mode, the lag destroy a lot of the perfect timing neccessary to perform the cool stuff.

Here are a few video of the more prolific characters in the game where timing is absolutely neccessary.

I won't even touch online mode.

Holy Shat @ the Cervy Combo video!

Some moves change based on when the move was released or the situation of the move. A blatant example would be with the psycho chick that I used to use, she has a crouching triangle I believe that on a counter hit does this chainsaw thing, but normally would just slice the target.