Have been on my brand new (4 months old) laptop, which came with Vista Business already on it, and my new Dev box (2 months old) which I put Vista Ultimate on. I had been dreading using it, since I played around with many of the earlier builds of it, and the performance on it completly sucked. I had upgraded my main machine to it after the launch, and it was dreadful and ended up wiping my box and going back to XP.

So far, my only recommendation about Vista is to get it as part of a brand new machine package (not some homebrew build, like I normally do).