Did you think it was clever or did you think it was cheesy? Did it add to the film or did it completely take you out of it? Just a basic survey.
I don't know if Nimoy's demanding these cameos or under some kind of contractual obligation -- but it was gratuitous. It mostly seems to be there so Prime Spock can reassure the audience that Khan is menacing and dangerous. Its ostensible in-story function seems to be to inspire NuSpock to an act of desperation, but he shouldn't have needed it by that point; all the pieces were in place for NuSpock to make that leap by himself.