Well, you also don't play Marvel as much as I do. That game really takes it out on a controller, trust me. It's not even just my D-Pad that's all worn out to hell, even my buttons are becoming less responsive from all the mashing that MvC2 requires. xD
I think I might get a stick in the spring, after I count what money I have left after my Disney World trip in the winter. It would certainly help with playing characters like Chun-Li.
As for KOF 2K2..... you test out the netcode first with other US players. If it works okay, I might get it to try out a Bao, Chris, and Benimaru team. (Oh, if only Ash were in that game... *sigh*)