to someone who says - as the person who wrote the item in your link has done:-
"After a month, I will have upgraded my test machine and will report the results in one of my newsletter in early September or so."
This is the person who is advising people not to 'upgrade'. He hasn't even tested the software himself, and yet he feels qualified to advise others. I've tested the software over its entire beta cycle - since December 2003 - and I certainly recommend installing WinXP SP2.
By all means delay your installation if you want to, but please don't base your decision on the advice of someone whose site includes such gems as:
"It's free to download, but there will probably be a nominal charge to get the update on a CD"
It's SP2 by the way, not XP2.