My tv screen is not that clean I can see a dark patches on all 4 corners of the screen when I tested for any dead pixels using videos from youtube and you can spot it specially when showing a full color background like white or green .Played around with the TV and settings a bit more last night and this morning. To be honest I'm pretty happy with the cinema day preset but with motion, mpeg reduction and noise reduction all off. For local dimming I picked medium, low didn't seem to make the dark parts dark enough. One thing I noticed though is that the local dimming has to work against the natural backlight bleed of the IPS screen. Mine has more bleed in the top right corner so the local dimming there isn't as effective. This is very obvious if you mute the TV and the mute icon glows on and off but in general TV viewing you don't notice it.
The screen looks pretty clean, sometimes DSE right down the middle but it's much better than my old TV which had several vertical bars. Slight darker patches in the corners but minimal.
HDR looks great, clearly brighter than my old TV. Had an issue with not being able to adjust any picture settings in Dolby vision IQ mode so put it on custom and turned motion etc off.
Playing media from my network works great and is fast, no buffering.
Overall I'm happy with the TV, so much better than my last one and it is very good for £500.
maybe I should send it back for a replacement.