Here is my HD20's black uniformity with the bulb on low. Forgive my test screen. It's just tacked to the wall. But will eventually be a clean and tight 124" 16x9 DIY floating screen.
I have one pic on paper with a 6" diag image really close to the HD20 bulb on low. And the 2nd pic is the temp wall screen with the image at 124" diag bulb still on low. Black image via HDMI from Laptop.
At least on monitor, it's pretty darn close to how it actually looks. I have also included a desktop wallpaper to show that you can't seem to see the issue with an image on the screen, even with no movement. I also just watched some dark scenes in Sherlock Holmes and don't notice the color tint uniformity. BUT, I do notice the poor black levels a lot. I know it will improve when my walls and ceiling are ultra dark, near black, dark grey. But I can tell that the extra brightness than my previous HD70 is really squashig the black levels. I even had my HD70 at 100" on low bulb. I think this HD20 really needs to be more like 150+ inches for nicer blacks. Just my opinion.
Below: Same test setup, just with a desktop wallpaper to show tint uniformity looks fine with an image. Blacks are certainly blacker in the photos.
Below: Black tint uniformity at 124" diag image projection, no ambient light, minimal wall reflection. Test screen tacked to wall. White 1.0 gain.
Below: Black tint uniformity at 6" diag image projection, no ambient light, minimal wall reflection. White paper.
Below: macro of the 124" image, same setup and time. Shows grey border around image from projector. Shows how different the black level is from the projector versus the white screen in the same room that looks pitch black in the image. So image the black screen looking dark grey and how grey that projected black border is. Is you are happy with Darkchip2 like the HD70, the blacks are a little lighter due to the brighter bulb even in low mode.