The first two screens I created were Sherwin Williams based. The first was white, with some blue mixed in because I had read something about an off the shelf paint like that which worked. That screen was OK. The second was a grey screen. It was better; not as bright, but it created better perceived contrast, depth, and color saturation. The third screen was a white Screen Goo screen. It was much brighter than either of the first two, but after a while I realized that I liked the grey screen better because of the blacks. These first three screens were all for a calibrated Hughes JVC G1000 with an anamorphic lense. It was a great projector in it's day (1365x1028), but by todays standards had a pretty pitiful contrast ratio, and anemic blacks. They were all in a dedicated theater room.
The fourth screen was a grey Screen Goo screen that went in my living room, the screen I just replaced. This one was in fact their Ultra Grey, with a stated gain of about .85. It has seen a Panasonic AE700, and Mitsubishi HC4900. It was noticeably better than anything I had used before, and I was quite pleased with it.
Edit: I forgot about the 92' DaLite Hi power and the 85" grey DIY screen I tried in the living room first. The Dalite arrived with the Panasonic, and is probably the screen I liked the least. The grey screen that followed it was a cheap test of the idea of a dark grey screen for the living room. If was made by wrapping material from a dark grey vinyl shade around a frame. It was better than the HiPower, and led to the Ultra Grey Screen Goo screen.
I am telling you all this to illustrate the fact that my conclusions are informed by a fair bit of hands on, extended experience.
None of my previous screens can hold a candle to the Silver Fire screen I just finished. This screen generates images with deeper blacks, more color saturation, better dynamic contrast, depth of image, and noticeably more detail. It achieves these deeper blacks while generating much brighter whites.
Now, I am not widely traveled in the AV world. I have not seen dozens of commercial screens, but I have seen a few. I have never seen another screen with my own eyes that can compete with the one I just finished. Ever.
I have zero interest in anything manufactured and sold by the commercial screen manufacturers after having looked at mine. The more time I spend with it, the more convinced I am.
Given that MM and PBMaxx say the RS-MaxxMudd is every bit as good in it's designated environment, I don't think you would ever feel the need to get a "real screen" if you take a little more time and effort to create a screen with the MaxxMudd.