For me, the killer feature is battery life. I used to have a macbook pro, but I'd get ~3 hours batter life at best (and only 2 hours, when doing heavy work). I

For me, the killer feature is battery life. I used to have a macbook pro, but I'd get ~3 hours batter life at best (and only 2 hours, when doing heavy work). I sold it, and bought a thinkpad x60, and get over 6 hours of battery life (4-5 hours under heavy load). I love that I can basically use it all day without worrying about battery. Pretty much any machine has a fast enough cpu for the kind of work I do - ram seems to be the big bottleneck now. (virtualization + firefox + emacs + python + sbcl + ... all take their toll).