The theatrical cut is missing a few great Spock scenes, but it's not a movie-breaking loss. The biggest issue really between the director's cut and the theatrical cut is the pacing. The film already looks fantastic
. The extra gloss given by the new effects is just an added bonus. The pacing of the theatrical cut is just way
more sluggish, but I suppose if you haven't accidentally broken the fast-forward button of your controller, then there's not much of a problem anyway.