I think my problem with it was how plot-driven the last episode ("Hated in the Nation") was. It ended in a way as if it mattered whether the cops catch the bad guy. I love cop shows, but the procedural bits here took time from all the interesting tech concepts that had been brought up. Another reviewer described it as feeling like an episode of X-Files, which I think is an apt way to describe it: Good, but not the kind of good that Black Mirror is uniquely positioned to deliver.