First off, I want to thank the people who gave me their opinions in the other thread. I took those into account, and those of other people, and then went ahead and bought an X-Arcade.
I'm curious as to whether anyone else has seen QA problems. When I got it home, I found that the right direction on the right joystick didn't work. I returned it to Fry's, and exchanged it for another. On this one, the right joystick, left direction (should generate "d") doesn't work. I'm almost positive it's the physical switch; I tried it on my wife's computer, and it didn't work there either. I also opened it up and shorted directly across the wire connection on that switch and got the correct response (a "d") without any hesitation.
I've got a third one on hold at Fry's pending return of number 2, but I wanted to send a quick note in case there's something else that's simple before I do. Any ideas?
Edit: Aside from the non-working switch, I'm really happy with it.