I am pretty sure it is exactly the same components except for the color capabilities of the RS20. If you go to JVC's web site they actually use the same exact flyer for both models and it is titled RS10/RS20. While the RS10 doesn't have all the same abilities to tweak colors, I have found it to be more than acceptable for common color problems like skin tones and the like. Where JVC's technology is different is that it is common for people to say the colors are over saturated. This is going to be true whether you have the RS20 or the RS10 I believe. When you see this thing in 1080P/24 at 12bit color however, the oversaturated primary colors (red's, greens and blues) don't stand out near as much. As an example, I had an upconverting DVD player hooked up to the projector that sent 1080i and the projector picked it up as 8 bit color. Scenes with yellow had a very yellow overall hue, anything red was REALLY bright red and greens (like grass) did not look natural. If I play the same movie on my PS3 that upconverts to 1080P/60 and the projector for some reason picks it up as 12 bit color as well, it looks tremendously better and i have read a few other reviews that also point out that the projector does not do as well with 1080i input. In some cases you don't have a choice (i.e. DISH), but thanks to another person in this thread, they suggested looking at the EDGE device that will upconvert every source to 1080P which the projector likes much better. Mine comes in on Friday and I will let you know how it looks, but the primary points for me are:
1. The RS20 is probably more tweakable as far as getting closer to the right color gamut, but when it comes to saturated primaries I dont' think that is going to help all that much (I could be wrong on this point).
2. If you spend some of that money you save by getting the RS10, you can get things like the EDGE box, which in my opinion is going to give you more bang for the buck anyway because the projector (RS10 or RS20), much prefers a 1080P signal and handles not only color, but the image just looks a LOT better.
3. Unless you know what you are doing with color correction and have the proper equipment, I don't know how much better off you are going to be anyway. I also highly recommend getting a calibration DVD ($30) as it really helps to fine tune your contrast, tint, brightness and color settings for your specific room. I had AVS calibrate mine and even though it was very close, for my lighting and room arrangement I had to tweak a few settings and without some kind of tool to do it, you shouldn't "eyeball" it.