I’ve only had it installed for about a half hour now, but it’s pretty snappy on my old system and even has some good Compiz effects running. I also like that Iceweasle is the default browser. More here
I have an older laptop that seems to get slower and slower with each update of Ubuntu. I once decided to kick Ubuntu out and install Gentoo on this laptop. It really was faster with Gentoo, but one update kill X and I had a hard time figuring out what killed it.