I've got W2K on my son's computer and XP on mine. If I had to do it all over again, I would have saved my money and loaded W2K on my computer also.
I see no advantages with XP over W2K, and XP is slower, plus I no longer can use some of my disk maintenance programs (Drive Image 4.0 and Partitian Magic 6.0 as they don't work with XP, and my great Epson 1240U scanner, which worked great with W2K, well, you guessed it, no drivers for XP and Epson isn't going to make any available.