From the http://forum.pimaxvr.com/t/details-in-8k-images-in-the-reviews/8279 thread...
The "bizarre" red pixel dithering appears to be a form of mura on the 5K+, which is something which makes me more likely to stick with the 8K.
Q: Have all the testers seen this, or is it only a problem for some 5K+ panels?
I'm trying to find a better image of the problem.
[update] Here are a couple of shots which show the problem. In the second shot I've blurred the screen, which makes the dots more pronounced and even marked an insert, identifying the dots.
If this is a pervasive problem on the 5K+, I think I'll stick to my pledge for the 8K.