2000 was very good but XP actually improved on its solid base in a lot of ways, its actually quite a bit quicker at certain tasks (boot / shutdown time in XP is less than a third of 2000s for instance), has better device support, particularly for the likes of scanners and cameras, removable media etc.
If you want a good no nonsense solid core OS, try NT4. Its rock solid stable, runs like lightening even on modest hardware (a full install of NT4 Workstation is less than 150MB
), the only major problem is it doesn't have any USB support to speak of. Thats where 2000 came in, it was originally called NT 5 until very late in the beta process.
That's what you're supposed to do with progress, take something good, and make it better. Fista managed to make it worse in virtually every area, that's some achievement