"Biggest screen" per se is not the sole goal of home theater, for most people. Enjoyability and comfort are also factors. If you're a front-row Joe, then go for it. Most people don't like being so close that they're swiveling their head to follow the action as it moves across the screen. At 65" from 5' you might be getting into that realm.As I intend to use the TV to watch films mainly it makes sense to me to get the biggest my environment can accomodate.
Isn't this the point of home theatre? To watch the films on a bigger screen as possible as the filmakers intended us to?
I suggest taking your tape measure to an electronics store and checking out watching a different size sets from your viewing distance to make you're you'll be happy with the choice. Doesn't matter what we say or what THX says: your money, your TV, your happiness.