The biggest problems with black mirror are similar to a show like The Twilight Zone. Making a show where each episode is different from the next can result in a mixed bag of quality. Seriously though black mirror is great because when it gets its satire right, it is truly unforgettable. I can't stop thinking about the Christmas special because of its fantastic ending. There are duds in this shows run obviously, but they aren't awful episodes. It's a strong show and there is not much more I can say

Also watch bandersnatch