The sad fact is trained professional projectionists are a vanishing breed. I've seen the quality of presentations go way downhill the past two decades. The guy working the snack bar is often the one who turns the projectors on.
The last time I had to complain about focus issues, it took three trips before anything was done and half the movie was over. Sad thing is, I was the only one who got off my ass to complain!
Two horror stories from different eras: I saw Star Trek 6 opening night, and the print already had a vertical scratch on the right side of the frame for the whole movie.
I saw the special theatrical screening of the remastered Star Trek episode "The Menagerie" a few years back. That was being broadcast (via satellite?) into participating theaters. Some dumbass had the projection system set at SD resolution! By the time I figured it out, it was too late to complain, alas. I think we could make an entire thread recalling the botched screenings we've all seen! ;)
Some film buffs have taken to calling digital IMAX "LieMAX" because it isn't film, but I've been pretty impressed with my local venue so far. I do think it's sad a lot of people will never see a true 70mm presentation though. Seeing Empire all those years ago in 70mm six track Dolby will always be a cherished memory for me. I really need to see 2001 on the big screen, and maybe a Cinerama film before I die.