I always preferred Win98se - and would still be using it if I didn't have to jump through hoops simply to get my flipping pendrive to work properly.
It would be easier to swallow if the designers wouldn't interfere so much with the way the desktop works.
But I have two identical SSDs on this computer, one running XP, the other W7 (for Elite D).
There is absolutely no doubt, XP is faster, by a not inconsiderable margin.