Bestbuy 55NU8000 has sub pixel dithering.
I went there recently and saw it with a magnifying glass.
The NU7100 does not.
I will provide pictures and possibly a video sometime before the holiday ends.
If you still have the 55NU8000 could you please use this pattern to check dithering by taking a picture of the last 6 color blocks on the lower left?
Update: Converted to Test Bench 1.2. Updated the results for audio format support via ARC/eARC, HDMI In, and Optical. Added Video Passthrough to TV results as well.