Hi,
I normally sit about 8 to 9 feet from my 50-inch 720p Samsung DLP and with good HD material, it looks terrific. As my Axiom colleague JC pointed out, the source material will also influence your viewing distance. Some standard-def (SD) can look fairly lousy, so I move back farther. On the other hand, some standard DVDs up-converted through the Oppo can look very good (episodes of "Lost" on DVD).
Blu-Ray of Lost episodes on a friend's 1080p set looks wonderful, so you could certainly sit closer than 8 or 9 feet with a 50-inch 1080p and good HDTV sources.
With front projection and large images, it really becomes a matter of personal taste. Everyone knows friends who love to sit up close in movie theaters, or midway back or farther to the rear. I don't want film grain from 35mm cinema prints to become too obvious, so that affects where I sit in a cinema and at friend's homes who have front projection LCD or DLP.
Have fun with your big screen!
Regards,
Alan
