The good news is that I just finished installing my projector.
The bad news is that it only fills 110" of my 120" screen.
Oops. I guess my room is not long enough. It needs about 16 ft distance to fill a 120" screen, but my room is only about 15.5 ft long. Damn it!
So far the picture quality and brightness is outstanding. And I only have the brightness on economy (low light).
I would say the PQ of the projector is the same as my 62" Mitsubishi DLP 1080p HDTV. Of course, I'm not an expert.
Another mistake I made is the screen itself. I should have spent some money and gotten a Carada or better screen. During brighter scenes I could see some vertical lines on the left side of the screen. I guess when I buy a new house, I'll have to upgrade the screen!
So far my conclusion is that the Optoma HD81-LV has outstanding PQ and Brightness. However, placement is VERY Limited so it's definitely not for everyone.
I cannot recommend the Optoma screen. It sucks. It's a good thing I only paid $200.
I'll have to post some pics later.