That said, there is one very real issue that I haven't seen mentioned anywhere: because of how thin they are, many of the minor issues that could previously be fixed in the Apple Store now require sending it out.
I had an intermittently working key on my keyboard and took it in for something I assumed would take half an hour to fix. They told me they needed to mail it in and it would be 4 - 6 days, probably 4. It's now going on day 13.
Fortunately my last one was old enough that it had zero resale value, but for anyone thinking of upgrading I'd highly recommend keeping a backup.