I didn't really like Cumberbatch as Khan. I think he was a much better villain than in the last one. So was Adm Marcus.
The last 30-40 minutes which became a reverse TWOK was much weaker than the first 2 hours which set up a good story between the crew vs Adm Marcus. That was a much more dramatic, and much better story. When Khan killed Adm Marcus he turned from an interesting character to a cartoon villain. And the story kinda fell apart from there. Not saying it was bad. I quite like the movie. But you had more cartoon elements than you did actual elements that were built over the film.
Cumberbatch was a good augment. I think if they just went with him as a counterpart to Khan this story works better because Cumberbatch just didn't have the presence t hat role deserves. He was really good and gave some solid moments though and was a far better villain than in ST09 and probably overall one of the best villains in Star Trek movie history. The only reason that they made his character Khan in this film was to have the scene where Spock yells his name to re-enact TWOK. But even that was flat compared to this one because of how much drama was built into that moment in TWOK.
The stuff between the Enterprise Crew and Adm. Marcus was much more interesting overall. It was all set up over the course of the movie. It was much better framed. The last 30-40 minutes Khan pretty much became a cartoon villain and little more. You didn't see any real motives for doing what he was doing for the most part. Which is pretty much all you got in TWOK.