But as I heard, Windows 7 uses as much resources as XP (or close to) and if it's similar to Vista, then I don't see why one wouldn't upgrade to 7.
Of course perhaps the reason why Vista runs fine for me is because I got 4 CPUs in my tower to run it.
7 uses less resources then Vista but more then XP.
7 & Vista have a lot more in common with each other then vista to xp or 7 to xp. Vista & 7 share the same kernal, differences are mostly cosmetic & under the hood optimizations.