I "knew" that stuff like black adjust and advanced contrast enhancer HAD to have downsides...... so I went and found them
Here's an imgur gallery with some pictures I took of Star Trek Beyond UHD, played from my oppo203
The first image is the extended info, showing the movie was mastered at 1000nit peak, and 0.005nit black level. Interesting. For some reason planet earth ii actually does not have this mastering data reported. I'll also just add that in terms of HDR WOW factor, planet earth ii is on another level from Star Trek Beyond. The improvement over the HD Bluray in Star Trek is noticeable, but planet earth ii had my jaw on the floor the entire time in its HDR presentation...
The set of images in the gallery above is from a little bit into chapter 5, 44:20 through 44:30. The first set is at 44:25 and the second set is a few seconds later.
Exposure and focus were locked for all but the last image, and I purposely overexposed the images to try and illustrate the differences. Pics taken w/ my iPhone 7.
1st image - Black adjust Off, ACE Off - lets consider this, "As intended"
2nd image (exposure/focus lock from 1st) - Black adjust High, ACE Off - the difference may not have come through in the pictures, but setting black adjust to high sharpened the transitions to black a little bit, but didn't really lower black levels overall. Light transitions on Simon Pegg's red outfit are a little sharper. Interesting.
3rd image (ae/af lock from first) - Black Adjust OFF, ACE High - here overall black levels of the shadows are reduced, the shadows in the upper right quadrant are much darker and detail in the doorframe above the ramp is harder to see.
4th image - black adj low, ace low - looks pretty good. Similar reduction in black levels from ACE high. Overall detail seems to remain intact. Pleasing picture.
5th image - black adj off, ace off - this is from a few seconds later when the woman leaves the room and walks up the ramp and through the hallway. Its a dark scene overall. With black adj and ace off this scene has a nice look to it as even though its really dark, you can see enough details that you get an immersive 3d feel of walking through the hallway with her.
6th image - black adj low, ace low - this is where the problems start. Much of the detail of the doorframe and hallways is lost (ace is doing this, black adj does almost nothing in this frame), some of the womans outfit is darker and harder to make out, but importantly in motion you lose the immersive effect as she goes through the hallway it looks like she is just walking away into darkness. Overall black levels are much darker, and the surrounding details in the scene are just a hair brighter than the black bars on top and bottom. An, "oled" like picture if you will
7th image - same as above but I let my iPhone do auto focus and auto exposure on this image to see if it might capture the overall lower light level coming from the TV better. It does seem to, and the picture shows a more representative level of shadow detail etc which is actually being reproduced.
So overall ACE and Black Adj seem like an interesting and/or good idea based on Sjchmura comments about Horizon Zero Dawn and other titles, my pics of Skyfall, and just overall impressions. But unfortunately its not a free lunch and I do hate to lose shadow detail since the z9 does such an excellent job of it.
One last comment, this movie has a ton of film grain in it. Setting smooth gradation to low does a good job of making it so that you never see banding. Setting to high smooths out and smear a lot of the film grain so if you hate grainy movies maybe try a higher smooth gradation setting and see if you like it.