I'm in the market for a 52" LCD and I think I have it narrowed down to these two sets. I can't seem to find much (if any) info on the 648 however, perhaps it's too new? From what I can tell, the only differences are that the 648 has built-in Dolby and has something called Crystal-Coat contrast enhancer...for $400 more. Anyone know more about the 52XV648U? Is the 52XV645U my best LCD bet if I'm looking to spend no more than 1600-1700? I also checked out the Sharp LC52D85U but people here seem to reccommend Toshiba over Sharp every time?