my room is like yours and not too large, with the walls being just shy of 12" from front to rear. we previously had a 55" rptv and sat at about 7.25' away, yeah im a movie nut, i admit it. on occasion we would move the couch up another foot, but the sd material just degraded to the point where the larger field of view was not worth it.
we've since moved and figured we could go larger considering the 2' we save from just the size of the set itself. ironically, its the gf that is lobbying for the 60, especially considering the price (about the 5010's retail).
iv thought about putting the extra 1k into a bd player and the like, but figured i could hold off on that and enjoy a 40% larger screen with the hundreds of sd dvd that we already have; thats if it can do an admirable job of scaling them.
and a sub