I have to say I actually really like that layout, I've always preferred the mobile version to the real thing for some odd reason. Although I've been on the waiting list for this layout for quite some time now and I still haven't got it, in fact I'm on the waiting list for a lot of things on Facebook that I never seem to get -_-
To me though, this design just fits well with my idea of good design. Maybe it's the colours or the layout, but it just works for me. Seems a lot simpler than the rubbish one I'm stuck with now anyway! Although Facebook are really changing a lot of stuff lately, that part of it is annoying, haha.