Sokurov is alone in the universe of known-to-me filmmakers in that he comes up with wonderful ideas for movies but is terrible at making the movies themselves (for a demonstration of both, see especially Russian Ark). So much so, in fact, that letting someone tell you the central concept of a Sokurov movie is pretty much the same experience as watching the movie, except, of course, for the duration. On the one hand, that's good, because very few people can come up with a truly poignant movie concept. On the other, it's bad, well, because the movie itself is.
So what is the central concept of this movie that's so wonderful you say? It is this: that Hitler, Goebbels and the rest of the Nazi high command were just people, and not particularly extraordinary or intelligent people, either.
Some of you will go "no f***ing kidding!" but really, that's something that is forgotten too easily and is a frightening fact. The atrocities of the Great War and Holocaust are somewhat explainable if one considers Hitler to be an insane genius, a man of pure evil. To see him as a dumb short guy who likes to get his belly poked by fat blond women, well, that's much scarier, because then how do you explain that this man caused the deaths of tens of millions of people? The thought is a harrowing one, but it is immediately understandable in the movie, and so there's no real reason for about 100 of the 108 minutes of its length.
Moloch is the cinematic equivalent of a post-it memo to yourself that you wrote some time ago and see just in time to act upon its instructions. If you remembered the contents, you're annoyed at having wasted the time to write (watch) something so obvious. If you didn't, you're very thankful for the note, and yet annoyed at yourself for needing the note in the first place.
So should you see this movie? Not if you've read my review or had someone tell you the gist of it. If not, it is necessary, if boring viewing.