I had similarly bad experience with my x220. If you try to boot with external screen connected, the screen blinks like a strobelight, you need to change resolut

I had similarly bad experience with my x220. If you try to boot with external screen connected, the screen blinks like a strobelight, you need to change resolution to make it work. X hangs up sometimes. Ditched unity, running xubuntu seems to be smoother and more sane.