I have seen the 3 different systems a 12 footer, a 14 footer and one 65 footer,some of it was spectacular up-converted (Yogi Bear)other upconvert content (Harry potter) looked lossy, have a big pictorial report to submit from Show East, but not this week.
The best was 65 mm transfer to 4k Sound Of Music (with exquisite film grain intact), here:
Clearly however fantastic for HT, and the future of it....
No native 4k shot content was shot, but on the smaller screens everything looked fantastic, the real-time up-converts of heavy laden special effects movies were the more tasking ones, though the yogi Bear is proof that 2k-4k can look incredible on a 65 foot wide.
Here is a 35 mm convert (You would love this Art) shown at 12', impeccable.
New DP-2k-p has a triple upgrade path, from 2k HC, to 4k, HC, to 4k, variable C.