It's no good. I'm glad Amazon has a good return policy.
There are 2 problems:
1.) It's just not good for steering the driving games I tried (Pole Position and Cruis'n USA). I'd much rather use my trackball than this.
2.) Unless you only have 1 joystick device on your system, the XBox 360 wireless devices are not a good idea. The problem is that whenever they go into standby (after about 15 minutes of inactivity), they are no longer seen by the system. Then any joysticks with higher IDs are no longer mapped correctly in MAME (for me, this is at least my 2 lightguns which have the buttons mapped as joystick buttons).
I also bought a wireless XBox gamepad, and I did think the analog thumb pad was pretty good for steering at least in Cruis'n USA (not as good as a real wheel of course, but it was fun). I don't think I got it configured well for Pole Position, but maybe with more time.
I'm returning all this stuff now, and I'll probably try a wired XBox 360 gamepad.