I've been posting individual small reviews on each episode within Black Mirror's latest season, which was released on Netflix on December 29; those reviews contain a few points of mine, but obviously contain quite a few large spoilers as well. This general overview will hopefully help people decide whether to watch it or skip it.
Black Mirror's fourth season is a very different Black Mirror to what we've previously known. We're introduced to some very new narratives, but ultimately they don't feel like the dark and anxiety-ridden show that explores various dystopias in which technology has reduced humanity in extreme manners through very minor changes. Technology removes our ability to act and feel as we should; and instead changes us for the worst.
In this season, very few episodes give that feeling: at best we are introduced to strange technological concepts that aren't all that bad, but have the odd hiccup that results in a few minor inconveniences for some; it's very different to the likes of previous episodes in which everyone is affected by these technologies. The episodes result in very little weight, little substance outside of an indie short film style.
The episodes with some weight to them feel almost rushed; rushed in an almost worried feeling, as if the episode's themes weren't strong enough to really take further, so we're left with many questions. It's all very hit-and-miss, but many episodes are still very much enjoyable. The season isn't bad, but it doesn't feel like a season of Black Mirror. If you have high expectations, it's going to feel very bleak and disappointing.