Points to note: when it first came out, I had to come up with a patch of tp smapi to get it to work. Not sure if that's still the case. You'll get inferior battery life in Linux, even worse than in Windows 7. I'm typically getting 5-6 hours on wireless doing not particularly intense stuff. Also some oddities with the special ThinkPad keys that's simply a matter of not caring enough to fix. Touchpad a bit funky.
It's a solid alternative, though I think I mostly chose it for a superior GUI, not the system itself.