The very thing
Avoiding Windows 8 and Mac Mountain Lion are the reasons I went to Linux. I tried Linux on an old machine before Vista came out without success (Linux didn't get along well with the hardware), so I moved to Mac for six years. But now THAT old machine won't accept upgrades to Lion or Mountain Lion, and I don't like the closed environment Apple is moving toward. So I got a new Lenovo laptop, installed Ubuntu 12.04 and have been more than happy ever since. Unity bothered me for about a day, until I read a small article on how to use its primary features.