I use an X45 stick under XP, I do not use the rotors(yet). I tried Saitek's SD02 that was just released and it hosed up all my USB devices. I had to unplug it all reboot and reinstall all my other USB devices, not to mention the BSOD, and the fact that it worked for about 2mins in game before the controls went haywire.
I currently use Dhazummers(sp) drivers and they are rock solid, just cant use the rotors yet unless you map them as an axis. I wont be going back to Win98 ever again.