Earlier quoted context omitted.
Just to add another data point, Arch Linux on X220: 1. 4-6 hrs with 6 cell battery. 2. Yes, Intel everything (HD4000, wireless, etc). 3. Yes, 1 resume crash total this year. 4. Yes, attached to external monitor via DisplayPort -> DVI right now. 5. Never tested. 6. Small, crappy. I'm one of those guys who disables the touch pad in favor of TrackPoint though. 7. Much better IMO, not a fan of chiclet style and Apple's "…
The problem is that these are exactly the kinds of replies given by Linux advocates throughout the years. I've used unix varieties for more than 20 years and never experiences like this for anything, ever. Nothing is totally supported, or works right away. Ever. At least not in the way a Mac user would employ those descriptions.
I'm tired of dealing with ACPI / driver issues as well. That's why now I just buy ThinkPad and Intel-only chipsets. If you're going to use Linux, you have to research your hardware ahead of time (e.g. poor Atom support) or buy Linux laptops (Dell Ubuntu series, unofficially ThinkPad series).
I'm not trying to say everything's happy in Linux land. Printers are still a sore point, as are AMD / nvidia cards (Open or binary drivers? Multi-monitor support?).