1.1 Gain for $800, or .85 Lunar for $1400.....is .85 really going to get me $600 worth of better PQ?

Just picked up a AE7000 for my living room...light controlled...60% Bluray viewing, 20% Xbox FPS gaming, and 20% regular cable viewing. This is replacing the main TV in the house (yes I don't mind replacing bulbs more often).

From all the reviews and a few in person looks at all the DIY options I decided that I want to go with a "real" screen. I have a it narrowed down to the SI Theater Sensation Fixed 1.1 110", or the Performance Fixed .85 110". The one thing I have NOT been able to review in person is the difference between 1.1 and .85 grey gain

I'm pretty sure I'm not going to be doing too much 3D viewing, which is pretty much the only con I read about the .85 gain screens (making the picture too dark for a good 3D experience)...so I'm pretty sure I want to go with the "much better" picture quality from the .85 screen over the 1.1 (from what I've been told by some questionable salesmen)....but am not sure if the extra $600 will really be worth the "much better" PQ.

I guess another question, for anyone with .85 or any other negative gain screen...is the brightness really that affected? Say you have a 1.1, and .85, and someone turns on a lamp in the room, does the .85 image just totally wash out while the 1.1 is still viewable as some make it seem about grey screens? That would be another deciding factor for me. I know it's all a trade off for contrast/PQ vs washout....just trying to make the best of this decision, and after shelling out $2000 for the PJ it would be nice to save $600 if I could.

Thanks

Thanks for the reply Bob. I was concerned about the brightness but was told the 7000 was bright enough for a negative gain screen so I figured it was OK. I used the calculator for the 7000 at PP.com and when I set the gain to .85 it goes right to middle of the "green zone" which is "recommended for low ambient light" which is pretty much what I have....when I bring it up to 1.1 it goes into the "red zone" which is "recommended for ambient light"...but I guess this isn't taking into consideration bulb life which you brought up.

If the 2000 lumen AE7000 isn't bright enough for a neg. gain screen, why do the grey screens seem so popular? Are they just for people with 5 digit price projectors with very high initial lumens? I guess I'm leaning towards the 1.1 now!