One thing I really dislike about digital projection: imagery that is dialed out of focus on purpose. Just about every d-cinema equipped theater does this in some manner. Even the IMAX Digital theaters do it (in the 2D shows that 2nd projector is there to aid in the fuzzing process).
There's two reasons why digital-equipped theaters have to do this. 1.: Obviously they don't want the pixel grid to be clearly visible to customers; an electronic looking image is highly undesirable. 2.: Moiré. Most cinema screens are perforated with either a square or hexagonal pattern of tiny holes which allow the speakers to project sound through the screen. Unfortunately the pattern created by those holes can't line up perfectly with a fixed pixel grid thrown by the digital projector. A precisely focused image is liable to hosed with moiré.
This wasn't a problem with film-based projection. The film grain on a 35mm or 70mm print is randomly spread. It won't clash with the dot pattern of a perforated cinema screen. There is no easy fix for the screen problem. A screen manufacturer can try to randomize the dot pattern of the screen perfs, but since movie screens aren't made all in just one piece the tile borders of randomized dot patterns will be very noticeable.
As film dies off so will the opportunity to see a tack sharp, perfectly focused image from a projector, at least not until someone comes up with a ground breaking change in how movie screens are made. It wouldn't hurt for the movie industry to drop all the 2K low resolution stuff either.