Counterpoint: I chose the ThinkPad X220 because it was on that list and it works (nearly) flawlessly under Linux. The only problem I know of is that the mic mute button doesn't work. That's it.
There is a host of other issues, but nothing that can't be worked around after hours of researching blog posts and manuals. More kernel panics on suspend (related to the aforementioned USB wireless), external monitor issues, USB 3 port disappearing ... You know, small stuff.
[1] RTL8188CE 802.11b/g/n WiFi Adapter (in my case, anyway)
[2] SMCWUSB-N2
Under a different set of circumstances, Natty could have been said to be flawless on my T420, and indeed I thought it was for the first few days. When I started using the system more intensively for the tasks I bought it for, I began to notice the problems.
- Distro: Ubuntu, then Fedora
- Compositing: Yes
- WM: Mutter
- Uptime: weeks, currently 15 days
- Multi-monitor: haven't yet, I could try and let you know what happens
- 802.11n: No