The only thing I can seriously fault with X-Gaming's buttons and sticks is that they're clicky. Really clicky. All microswitch-based controls are clicky, but X-Gamings take clickiness to a whole other level.
Buttons are good, but all buttons are generally similar. I like the feel of the sticks; they do have a very short throw though, so keep that in mind if you like a nice long throw on your sticks.