I run xp, however the reason I run it is because it's got a nice remote control feature built into it. I have two computers and It makes it very easy for networking when I only have 1 monitor. However If I had to choose between the two and only had one computer I would choose win2k.
I like my OS's to be basic and whatever I want or need I will download. I don't want to search for all the things I need to uninstall. There is a great page that will help speed up your XP if you decide to install it:
www.blkviper.com
just look at all the crap that is running. XP loads soo much slower than win2k ever did. just my 2 cents.