Like others said, its all really a matter of preference.
I know that Xbox 360 pad is a poor choice for fighters, yet several of my scene's top SF players use Xbox 360 pads so there is always exceptions. Myself, I had to go out and get a fight pad within 2 weeks of me picking up SSF4! The main reason I switched to stick is because my main in SF4 ( Juri ) was being limited by me using pad, I can do so much more with her now since I made the switch.
As I can use stick now, I generally strive to use it for all fighting games, SCV being no exception. I use a lowly Hori Ex2. I know people say its cheap, impossible to mod and whatnot but it does the job I want it to do and I don't see the point in getting another stick if I'm going to be travelling later this year.