We have had the sheetrock theater screen in place for about and 3 weeks, and we are very happy with the results.
You get good contrast, but the picture is not too dark. Overall, the Behr Silver Screen paint (flat) seems to be just about the right color. If I were going to change anything, I may make it just a bit lighter - but at this point I am not changing anything.
I would take a picture of a movie playing, but I can seem to get a good image with my camera in the dark room.