The virdict is out. Its lot more slower than XP SP2. Cool new addinium. Some claim there is more stability but for me, XP is stable and robust enough apart from that most software of use work on it.
Microsft is coming out with SP3 for XP which is good news for India which would increase speed by 10% over SP2 also a SP1 is expected for Vista to improve speed.
Hope you made right upgradation choices.