Of course, you should be satisfied not only with how the character behaves but also the look.
Even if there was a character who had the fastest jabs, easiest and most damaging kombos, was the best zoner/rushdown/whatnot-character of them all, if he/she would look like crap, i would not use it.
If they would bring odd-looking characters that seemed totally out of the MK-universe, like Tron Bonne, Amaterasu, Viewtiful Joe to the game, even if they were the best, i would NEVER use them.
It's about kicking ass, and look good while doing so as well!
I myself have no problem with the look of ANY character-design in MK9 so far.
Looking forward to Rains design as well as Fujins.