The Buffalo/iBuffalo is pretty much the best of the SNES style pads you can get right now.
All of the cheap ones have dpad issues that make platformers like mario really difficult to play. You just get unintentional direction presses. The Buffalo doesn't have that kind of problem. Side by side with a real SNES pad you can feel that it's not built as well, but functionally is pretty good.
I'd also recommend the hyperkin gn6 pad. There are genesis and USB versions of it. Although hyperkin's snes style pads aren't great, the genesis pad is imo as good as the buffalo snes pad. I guess the genesis dpad design is just easier for the generic makers to get right.
You probably bought your pad a month ago, but maybe this will help someone else.