Almost all the complaints I see about Vista or either misinformed, or about "UAC" (that little box that pops up saying "are you sure you want to do this", whenever you try to do technical-y stuff).
Apparently some of these self-proclaimed "pros" don't realize UAC can be disabled in less than 5 minutes. I disabled it on my PC running Vista, and I must say, since doing this, I've found Vista to be much better than XP! Of course, I never really liked XP... (probably due to "stylish" redesign... I still use the '95 style layout for everything! I think if they ever removed the classic style GUI in a future version of windows, that'd be enough for me to switch to Ubuntu for everything... =p )
EDIT: Oh, yeah, it needs more RAM, that's the other thing. But it also supports more RAM. I'm not the sort of person who goes out to buy a new OS by itself, only when I get a new PC, so I never had any problem with this.
EDIT2: Actually I do have a problem with Vista, my ancient publishing and photoshop programs (Serif Pageplus 9.0/Photoplus 9.0) don't run that well on it. Kinda lags a bit. But that's not really Microsoft's fault...