Back to the Future 3 (UHD)
PQ-wise, they "saved the best for last." Having said that, it started out a "mixed bag" with sporadic "soft shots" resulting in poor resolution and a lack of details and depth. I also detected some "noise" in a couple of those scenes. Other scenes were very good, though not "reference quality." Then at about one-third way into the film the PQ really "came alive" with unbelievable SHARPNESS, exemplary DETAILS, inky BLACKS, and incredible DEPTH. It was "Reference Quality" all the way to the end! Colors were pretty good, though there was a fair amount of "color-grading" (orange hues).
This is a hard one to call. If the whole film was like the second half, I'd easily nominate this for the middle of Tier 0, but when putting everything on the scales, I figure it was about the same as BttF2. So my vote goes for....
Tier Recommendation: Tier 0* (.9)
PS I simply couldn't resist going a tad higher due to the EYE CANDY in the last half to two-thirds!