The only time I use Win2K is for systems with 256MB RAM. I'm not too keen on XP on them, though I'd imagine the memory requirements aren't that far apart.
I don't see the big problem with XP. Control freaks, all of ya!
XP and 2K work Sooo much better than 9x in every conceivable way. The fact that they are entirely 32-bit alone makes a huge difference in smoothness, stability, speed, security.....even on old systems (P6+), assuming they have enough RAM. DOSBOX can support all your DOS needs if you're a DOS nut.