I've been using feisty on my x20 for about a year and it works fine (after
compiling the module for my pcmcia wireless). Especially, I was able to bind gnome commands to the special keys - volume, and ThinkPad.
I now installed Hardy to see how it is. Among other things, I can't get those special keys to work. If I run xev I don't get any response when pressing them. Anyone have an idea why?
Another feature that works in feisty out of the box but not on hardy is
speedstep - my 600MHz p3 doesn't scale down to 500MHz when idle.