Vista is only a memory hog until you trim the fat. I have a Lenovo T61 Widescreen and got it with Vista 3 months ago. I've had absolutely no problems with anything or even compatibility.
As much as people give Vista a bad wrap, they just don't want change. The ReadyBoost is great, and I've got a USB Drive with 4 gigs also speeding the processing up when it's on.
All I really suggest if you get Vista is to go to services.msc and disable 3/4 of what you don't need. You'll notice your ram frees about 1/2 of what was taken.
Remember, no one originally wanted to switch from 98 to XP but now it's always been a solid OS. They've always got less problems than Apples