Okay, so I sat down with both versions cued up on two players (OPPO and the Sony X800) going into my ZD9, each HDMI input set to the exact same picture settings and each player presenting as unmolested an output as possible. To my eyes the grading is literally identical. One isn't dimmer, one isn't darker, they're exactly the same in terms of black level, colour, highlights and mid range. This, my friends, is the benefit of a HDR TV that ignores the metadata completely: it takes the content as it comes instead of trying to pigeonhole it according to the size of the container. IMO that is EXACTLY why some folks are saying the Warners version is too dark, the TV's tone mapping is looking at that 10,000-nit mastering container and busting it down to size, regardless of the barely-nudging 500-nit content that's actually inside the container.
Comparison photos below, Sony top and Warners bottom. Do NOT take them as being indicative of what the HDR version actually looks like as these aren't my usual SDR to HDR comparisons, they're simply to show the differences or lack thereof between the two UHDs at any given exposure. (Any tiny colour variances are purely due to the exposure)
Sapper's abode:
The man himself:
Simply Luvleh:
Dem bones:
Wake up...
I did find something that does set them apart though, following on from what Vangeli reported ealier in the thread. Not long into the Sony disc I thought to myself "does that look a touch sharper?", as from that first shot of K's hand in the spinner it just seemed to be that little bit crisper than the Warners version, and this continues throughout the film. It's most definitely NOT some kind of massive life-altering difference but to my eyes it brings into play the talk about this being "reference" for sharpness, I was not wowed by the sharpness of the Warners disc (hence my blah reaction to it upthread) but however slight this Sony improvement is, it seems to make all the difference on my 65" TV. Take the scene of K after he's had his baseline test when he first returns from Sapper's, when we get the wider shot of him facing camera the little holes in his jumper are more distinct on the Sony than on the Warners. It just seems to have more precision, more 'snap' to the detail.