There's more to XP than most realize - the stability issues are worth the upgrade alone. All my games (especially MSTS and Trainz) run smoother, look better, and have less crashing.
Memory management is also enhanced - I'm currently running 1Gb of system RAM. I upgraded to XP-Home, as I didn't need the networking features of Pro. All in all, the best $90-bucks spent in some time.

Cheers!
Marc