I enjoyed the movie but I never bought Cumberbatch as Khan. Sorry, but he never sold me on that one. At least with Kirk or Spock I can see at least SOMETHING in their performances that makes me say "Okay, that is him" . With this new Khan the accent was wrong,the look was wrong, mannerisms were wrong.... They should have created their own character rather than recycling Khan.
They also need to quite bringing back old Spock to explain everything. The torch has been passed. Let him fade into history already.
I agree about Spock, that was completly unnecessary.