Once service pack1 was released for XP it became as stable as 98se if not more. Prior to that, i had more crashes, reboots, and blue screens with XP then 98se. I had a gig of ram so that was not the cause of my problems, i just think when it comes to certain OS it's best to wait for the 1st service pack to come out before even thinking of waisting money on it. Even on the speed side it's only after service pack one that i managed to beat my old bench score.
I think so many people stil run 98 because with all the patchs ans packs it's almost as stable & as fast as xp and it does not cost of the xp upgrade (150$ can) or full version at $300 can! At that price you can get a new video card or 2 SATA drives running raid0 or even a new cpu!
Bottom line XP is way to expensive for the performance improvements it brings! If you get it with a nes PC then no need to go back to 98.