See here:
http://www.firingsquad.com/print_article.asp?current_section=Hardware&fs_article_id=2265

Quite interesting.

I also seem to recall that for good home hifi, bigger is better

Basically people asked to rate how they enjoyed a film rated bigger screens more than higher def screens.

Of course I have a 2.8m projector that can do HD but usually does SD so I would say that