I checked out the UK 4K disc release of one of this year's most spectacular films. I purchased the US blu-ray in May and saw it again in IMAX this summer. As I typically experience, projected on my Optoma/Oppo 203 set-up with the HDR turned off, the picture is much darker than the blu-ray and shadow detail is lost. Also, the colours seem drained, compared to the blu-ray. I expect anyone watching it on an OLED flat panel, with HDR activated, will experience a completely different colour saturation. I thought the blu-ray was really good up-rezzed to 4K and I couldn't see much difference to the 4K disc on a 150 inch screen. It wasn't like It's A Wonderful Life, where the grain was much more prominent on the 4K disc, compared to the blu-ray. It will be interesting to hear reviews from other people.