Testing the UHD4020R for VA colour shift: https://www.youtube.com/watch?v=xV8qGnlMUXc
The camera picks up how you see it with your eyes pretty well. The part in front of your eyes is bright, and everything else is dim. It's not noticeable on scenes with lots of different colours, but on a solid white or grey background it's pretty clear.
Default FreeSync range 48-61hz. I will report back when changing the EDID to see if I can expand the range southwards.
In Windows 8 colour management I had to bump gamma up a tiny amount, and turn Green down 2 notches, otherwise all default settings were good. There doesn't appear to be any colour uniformity problems, and if there are any dead pixels I haven't found them yet (bought from accessorieswhole on ebay. non-perfect pixel version, but nonetheless no dead pixels that I'm aware of)
EDIT: It's a BGR panel. I don't really understand how to use it, but the Response Time test here: http://www.lagom.nl/lcd-test/response_time.php#response_time_gif has A, B, C, D all flashing red constantly. E onwards is not flashing.