I was looking in the blu-ray.com forum thread about the 4k release and came across this compare (link), which was a bit 😮 to me. Note that I’m not a possessor of these disks, haven’t watched anything in motion; this is just me pointing out stuff others put up, which may be quite “cherry picked” by one of the more frustrated persons there.
That said, I’ve never quite seen something that struck me as much in regards to cranked-up DNR doing damage (well, excluding the dress in Cinderella!) and in an image that’s ideally supposed to have a lot more resolution(/detail) than the BD…
Luckily, people in that thread generally say the good of the 4k set outweighs the bad, sometimes by a huge margin for some, so this compare is surely more just a blip of excess DNR rather than an indication of the whole set being remotely like this.