I finally got around to watching Don Darko UHD Blu Ray a couple weeks ago.
I'm assuming most people reading this have already seen this movie, but in case you haven't, the following does have some spoilers.
I had the director's cut in 1080 HD previously, and more recently bought the UHD disk (also director's cut). It's been quite a while since I watched the HD version, and I watched it on a different system. I have not tried a back-to-back comparison of the two disks on the same system, so my impressions of the UHD compared HD are based on memory.
The UHD package I bought came a with a UHD theatrical release disk as well, but I have not watched that yet. Quite a few reviews online state that the UHD theatrical release disk is defective and will not play. Just an FYI.
Overall, I thought the sound track was better on UHD, but I didn't notice a big improvement in picture quality. My impressions are more or less the opposite of other reviews I've seen, so I'm wondering if my impressions might be due (at least in part) to differences in my 2 systems. I'll try watching them back-to-back on the same system and update accordingly.
If you like 80s music, it's almost worth watching just for that. The sound track seemed to be almost perfect. This may be due at least in part to the Philharmonic BMRs in this system. During the party scene near the end, the music was exceptionally clear. The information I've seen online states that the audio track in HD and HDR are the same, but my ears tell me they are different. Having said that, my hearing is far from perfect and my impressions may be based on differences in my 2 systems.
Overall, the picture quality was very good, but I watched it on a Samsung QN75Q70RAF TV. Many of the scenes in this movie are quite dark, and I suspect that there may be improvements in the video that would be more pronounced in an OLED set. One of these days I'll pull the trigger on an OLED TV and watch it again.
As I understand it, this movie was originally filmed in 35 mm on a low budget. Basically, you know you're watching a movie, but I'm perfectly okay with that. (Richard Kelly: “This was the only film shot entirely on the Kodak 800 ASA stock. It had just come out, and people were saying it looked terrible and grainy. But I like grain.”)(https://www.indiewire.com/2014/11/lessons-from-legendary-donnie-darko-cinematographer-67544/
This may be an odd comparison, but I have Lawrence of Arabia on a 1080 disk, and this appears to be less
grainy than Darko in UHD. I attribute this to the Panasonic Super 70 camera and film used to record Lawrence of Arabia, but I'm not 100% sure this actually correct. If anyone has Lawrence of Arabia in UHD, I'd be very interested in your impressions, especially in comparison to HD.
Okay, here come some modest spoilers concerning the director's cut vs the theatrical cut. I like Darko because it's so difficult to figure out exactly what cr*p is going on. One of the major debates over the years is if Donnie is merely dreaming/hallucinating, or if there really is a parallel universe. In the director's cut, it's pretty clear there is a parallel universe. Some people apparently dislike this reduction in ambiguity because it shifts it away from being a "hybrid" (for lack of a better word) psychological thriller/sci fi movie to more of a sci fi movie. For me, there's still plenty of ambiguity/mystery in trying to make sense of the rules of physics in the fictional alternate universe. Also, for whatever reason, I tend to like sci fi movies better than psychological thriller movies.
Edit: I've been thinking about why I prefer the parallel universe interpretation. For me, it boils down to this: In the "parallel universe" interpretation the "other" Donnie is real and he needs to make a choice to die in the "main" world in order to save people in the main world (even though he recognizes that he will ultimately die in both universes). In the "dream" interpretation, Donnie has a weird dream just before he dies. End of story. It seems to me that substituting halucination for dream leads to a similar result, except possibly leaving open some additional ambiguity concerning which universe is the real one. For whatever reason, "real universe" with real choices is more satisfying to me. Given that it's all pure fiction either way, it doesn't really make much difference of course. As always, YMMV.
Overall, Darko in UHD is probably worth it if you're fan who watches the movie multiple times. My best guess is that an OLED TV would be required to really capture the differences between HD and UHD.