Terrific take on a cultural institution. Enough 'tags' from the original series to make it good for fans; enough new stuff to make it accessible for 'new to Starfleet' folks.
Belief had to be suspended in a couple areas (without giving away plot points), but it was minor. And they changed the entire time continuum, so a sequel is definitely necessary, but on the whole, I loved it!
The actors pegged for the major roles of Kirk, Spock, McCoy, Uhura, Sulu, and Chekov did a fantastic job (especially Spock and Kirk).