The RS20(HD750) is a terrific projector, the CMS though fiddley can be effective. There was a firmware upgrade. I have the software if you need it. I have a RS20 with an upgraded light engine from the RS35 series, 110,000:1 iris-15 on off contrast. Quite a number of folks got this upgrade due to a light engine failure. Including Jeff Meier.
I have a RS640 as well, the RS20 keeps up, a step behind in black levels, it's no slouch.
Edit: Agree with dragonbud0. I can understand a larger screen if you seating row/s are wide. Sit at the appropriate ratio and size becomes a non issue in a dark room. One's mind get immersed in next to no time. You have the advantage of reducing the manual iris aperture, thus gaining on/off contrast.
I have a 92" and a 106" screen Dalite High Power, projector runs at -15, maximising contrast. I don't use the DI on the RS640, just manual.
May the success of a Nation be judged not by its collective wealth nor by its power, but by the contentment of its people.
Hiran J Wijeyesekera - 1985.
Last edited by Highjinx; 06-25-2019 at 04:50 PM.