I enjoyed this episode as a child, but I re-watched it on DVD last night for the first time in over ten years and it was pretty horrible. The dialogue is weak, none of the characters act like they are really in danger, and, as others have said, Spock is written as an asshole. After watching this, it's easy to see why Nimoy complained about the dialogue in season 3. Yet I still find the episode watchable if only for the childhood memories attached to it.