I thought the Keenser story was weak compared to the redshirt story. It felt like an incredibly childish fable. We have disability discrimination legislation in Europe where employers have to make reasonable adaptations to the workplace yet a high tech spaceship with a history of anti-grav units makes an employee climb on a box? Shoddy. I was surprised that he's a lieutenant though, given the way that he is treated. I don't know if this is intentional or if it's a symptom of the writers ongoing obsession with the officer classes without giving much thought to the logistics of being an officer.
The Mirror story was good fun though. It will be a shame if it's just a 2-part story but they might revisit it in later stories I guess. Let's see if they can make the Narada fun and fill in some of the silly gaps from the movie. I wonder if Mirror SpockPrime will make an appearance in a cave?