Huh. I think I liked Black Museum more than Metalhead, to be honest, at least, as a Black Mirror episode. The latter was fine, very good, even, but it didn’t really have anything to say about society, or even technology really (subject to later spoiler filled discussion, perhaps). It was just a cool sci-fi short, well executed. Black Museum wasn’t perfect, but it was making a point (in many ways, the same point(s) as White Christmas, ironically). And it had the whole anthology vibe going too, like the Twilight Zone Movie, or Cat’s Eye.
I think my main criticism of the current season is that most episodes weren’t doing much in the way of social commentary, or even current tech trends taken to extremes. They were “just” personal stories with a tech angle. Nothing wrong with that, but not really what I’m looking for in Black Mirror. Still, I think it was pretty strong overall - no duffers, unlike previous seasons.