Well, the fact that your xfi card doesn't work in Vista has nothing to do with MS. Look here:
http://forums.creative.com/creativel...board.id=Vista for the facts. Firefox works just fine in my Vista, so I would suggest you look at the most up to date version and thus it is pointless suggesting you hold off for SP1 when in fact the problems described all lie with third party vendors.
Now, hanging on for an update for your windows 95 tetris game would be a good reason to hold off installing vista, but it irritates me when it's suggested that it's Microsoft's fault that a creative sound card doesn't have up to date drivers for the new os.
It's not. It's Creative Labs poor planning that has caused your sound card to fail in Vista.
As for ram, you're right, it does take time to address ram, but it takes longer to address HDD. Vista is eye candy, so demands more ram to generate all those pretty 'aero' effects, but typically, having forked out for your gigs of ram, the average user is going to run with one maybe two windows on the go, so the extra ram you'll need to run it will contribute to the faster, smoother running of your system. It's an arguable point - my pov is that this is in general, where home computing is heading, so I'm happy to sign up for it. You may see it as frivolous and wasteful if so, then xp or ubuntu is your natural home.