Well... It does have it's annoyances, but most of those can be fixed. It uses up too much ram - Solution? Look up a good guide to the services, and disable the ones you won't use. It really helps. Disable windows aero, and all the other fancy eye candy if you don't care about it.

DEP kills some games I try to play. That's just aggravating.

On my laptop, I can't actually get SP1 / SP2 to install! I've given up after a few hours trying to figure it out. Maybe I'll try again sometime.

On the upside, I've been malware free for the year I've had this, most weird crashes are isolated to programs, and I haven't gotten a single BSOD yet.