As a huge Star Trek fan, I was so looking forward to this movie back in 1979 but it was overly ponderous with all the Enterprise porn. I saw a cut on TV some years later that had a scene in sickbay with Spock crying that I haven't seen since. Here's a recut of the movie that's only 22 minutes long but contains all the essential bits:
RE: Insomniac Film Festival #9: Star Trek: The Motion Picture