Looking at jumping in on the 4805 deal, but this would be going in our livingroom/HT which has two windows in it. These are covered however some light still comes in.. Will it be dark enough for only 750 lumens?
I have mine in a well-lit room. We have two double-wide sliding glass doors running down a 40-foot wall along the right side of the projection path, and the wall facing the screen (behind the projector) has two more windows and *another* double-wide sliding glass door. I've got vertical blinds on all of that stuff, but no blackout.
I'll be honest -- I won't watch a movie on it during the daytime. It's just not worth it. Now and then I'll throw TV on it during daytime, especially if it's overcast outside. But that's about it.
This is really fine for us, given the fact that we simply aren't around during weekday daytimes, and on weekends we rarely have time to watch during the day either. I've got a plain-jane 27" TV positioned directly below the screen for daytime viewing.
But if your situation is different, and you *plan* to watch movies during the day, and you're interested in picture quality, then you really need blackout capability.
I think you'll be fine. Even with the lights on in my room the picture is viewable, but of course darkness is preferable. Don't let the existence of windows deter you because there are ways of dealing with them, if you're willing to go there. I would only say don't go for the projector if you are surrounded by glass and have no way/interest in covering them. Of course things get a little trickier during the summer when it gets dark later...