I literally hoard good condition X220s, dreading the day when they're no longer fast enough for my needs (hopefully a long way off still). It's the last (going by manufacture date) laptop I enjoy using. The keyboards are superb, the build quality is excellent, perfect compatibility with modern Linux distributions and the battery lasts 4-7h of real world use (6 and 9 cell versions, respectively). You can get models in perfect condition for 300-400 euros on eBay, and they still make new keyboards, batteries, etc. for them. It's the perfect laptop for those of us who dislike chiclet keyboards, the thin > all design fad and all the other maladies of modern laptop design. With Sandy Bridge i7s and 16gb RAM, they're powerful enough for my needs and thankfully let me write and debug AVX-capable code (with the usual profiling caveats associated with the SB architecture).
As for open boot, I understand the X220 supports both coreboot and libreboot, but I don't use either, so I can't comment on it in detail.
As for open boot, I understand the X220 supports both coreboot and libreboot, but I don't use either, so I can't comment on it in detail.