I bought a 5050ub from Projector Screens and couldn’t be happier with the product or the delivery. it arrived a day early, safe, and undamaged.
I run a constant height screen so the power zoom, shift, and focus with 10 memory positions is excellent. My only slight complaint is that it does take a minute to shift between formats.
The 4K is sharp without causing screen door effect. The zoom and lens shift dropped right in on the projector shelf in my theater.
I used a calibration disc to adjust the contrast, brightness, hue, saturation, etc. and it looks excellent after calibration.
I'm looking forward to many years of enjoyment!