Apparently, for some people, it "slows their system down to a crawl bawww" but I've used Windows Vista with 2GB and 4GB of RAM and never experienced this myself. Then again, I don't have lots of garbage running in my system tray and needles processes in the background, and I've noticed people with this problem generally do.
To be fair, during beta I tested Vista on a machine with 2gb ram, and an older 7200rpm hard drive, and the combination of the slow disk, superfetch and indexing, the system took forever to even boot into vista, and once it was there it was slow for about 35 minutes!
Disable superfetch and indexing and it was pretty nippy even on the rubbish hardware I was testing with.
On the other hand, on my main computer, with a good hard drive, I dont notice any slowdown from indexing, and superfetch finally does more good than bad. So really it does depend on the PC.
I have Vista on my office PC, as I do tech support, for vista users, so found it essential. But on my home machine I still use XP 64bit, and it does everything I need. Really no incentive to pay out more money for yet another MS operating system.
Next round of upgrades, I'll probably buy a Nehalem, loads of ram, Raptors etc etc, and go for Vista, while my current PC will be modified into an HTPC, media hub, and general file server using my XP license
