What about over heating?
I tried ubuntu 12.04, and 12.10 on a 2011 macbook air 4,2. I followed the information here, some of the tweaks weren't needed on 12.10:
https://help.ubuntu.com/community/MacBookAir4-2
But the fans were spinning almost constantly. This was with just firefox and vim usage.
OS X seems to do a better job of running Apple hardware at a sensible temperature.