I just exchanged my original rMBP purchase for a high-spec one after waffling for a couple of days with it unopened. Upon cracking open the new one, I've found that the keyboard is rather clattery compared to my MacBook Air, 15" work rMBP, or even the Apple Keyboard on my iMac. It's hard to describe, but it's kind of loose feeling and sounding, like when your finger lifts off you get a click. If you shake the laptop up and down you get a definite high-pitched shshshsh sort of rattle going on, maraca style. I don't get the same effect on my other MacBooks. Thing is that it's not like it's one loose key--it's all of them. So it seems consistent, if not intentional? I certainly don't mind exchanging, but don't necessarily want to send one to the refurb farm and get another one with the exact same issue and possibly a worse screen or something. Can someone comment on this, especially who might have been able to compare previous models of the flat keyboard?