Jostenmeat, I was wondering what kind of screen gain you recommend for the RS2.
Toughie.
I was looking at a Carada Criterion 110" at a throw distance of 12'6" from the screen to the lens, which will be using about 2/3 of the zoom. We will also be right around 12'6" seating distance (giving an angle from the edges of the screen to the center seat of 35.5 degrees). I have the options of 1.0 or 1.4 white screens, or a 0.8 high contrast gray screen. I don't know the gain on the screen in his old room for all his other projectors, and I am not sure we even had the option when we bought that screen...
Firstly, you can just forget about the gray. You don't need any contrast boost when your PJ says JVC on it. If it's a cave, I don't think you need any gain at 110". That said, I am under the strong impression that most gain ratings are over-rated. For instance, there's a consumer who had 5 screen materials in his home, and an Elite 1.8 completely paled next to the HP he calculated at 2.0 with angles. Then others say that sometimes 1.3 vs 1.0 is barely discernible at all (but it should be).
Since it's Carada, I give the benefit of the doubt that there is gain. Higher gain angular reflective screens do boost brightness, but typically sacrifice uniformity, and are more prone to hotspotting. Since you are only considering angular reflective, dark ceiling is a big bonus. If say you were using retroreflective, where the light is directed exactly back at where the PJ is, the back wall actually gets a lot of benefit, depending on the setup as a whole.
As with anything else, I'd just put the PJ in first on the screen you have. AFTER that, you can figure out if want to enjoy the blacks more, or have it brighter, etc. You might end up changing the viewing angle as well, who knows. (Which changes things: if say you doubled the screen size, for discussion's sake, getting a true 2.0 gain would have the exact same brightness and blacks as half the size at 1.0).
Really though, because you can, go dark everywhere. Sidewalls, floor, etc.
The room, which I will be tearing down to the studs and wiring then also probably hanging drywall and painting myself, will have dark walls, carpet, and ceiling (though possibly lighter than the walls) with no windows and one door - i.e. we can go as "batcave" as we desire. We will have some sconce lighting on the back wall with a dimmer on it that we like to turn up a little bit on rare occasion for playing video games or eating some of the messier snacks. Unfortunately we only have 7' ceilings to work with, but that is how it goes. Hopefully we can fit the center channel reasonably under the screen - we may have to tilt it up a bit for the best sound...
Definitely tilt it. If it's too close to floor, as it is with mine, treating the floor may prove to benefit you in reducing midbass peaking. I don't know if your pops is anywhere as interested in audio as with video, but I cannot recommend treating the room more. If you can only afford a handful of panels to begin with, I say front corners for bass, and first sidewall points.