It's a great family movie. Exciting and action-packed, but not violent. There's no on-screen deaths. And there's an amazing happy ending that feels earned.
So much nostalgia in that little collection! I truly believe that there were no bad TOS movies. They were all great in their own ways. We go from high-concept classic slow-burn sci-fi, to a tense naval battle between brilliant captains with major consequences, to an exciting adventure story for the sake of friendship, to a family-friendly non-violent fun romp through time, to a slightly silly story that's straight out of TOS but also has some fantastic moments with our main trio, to an action-packed mystery thriller that gives our crew a heartwarming send-off.
I would re-watch any of those movies happily. Yes, even #5. It's only "bad" by TOS movie standards. It's way better than any TNG movie or any episode of Discovery or Picard. Sybok's actor deserves a lot of credit for his work. He's that best and most interesting kind of antagonist: someone who thinks he's the hero of the story, and who thinks he's doing the right thing to help others.