Just to input a little.
I do miss XP to a point.
But I run Vista Ultimate 64 bit and have not had any issues with it.
Granted Vista does take a little more getting used to than XP and needs that extra setup proccess.
I find my machine runs great
Granted I do keep my computer updated and clean so maybe that could be part of the running smooth continualy.
I would rather Vista now than XP.
However I do not think I will be moving to Windows 7 any time soon.