I can tell you all--as somebody who installed the Black Diamond material a year ago--it makes a HUGE difference in the image being projected. It's like going from a blu-ray disk to a 4k with HDR. The contrast is better, the colors pop much better because they're not washed out by the white screen, and the viewing angle from all angles is terrific because the material is designed to be used in a home theater. I do think the price is high...I paid about $30 to get two samples from the company. But these are precut (cutting and fitting the pieces was a bitch), and he did have to pay for shipping to Europe (and shipping back to North America if it's included in the cost).
One question: How do you get it to wrap around the ramp and other curved surfaces??? It's such thick material, I have no idea how you could get it to stick reliably. I just left the white panels on my ramps and did the main screen and all the targets.