I'd like to read Matheson's original version of the script before it was re-written by Roddenberry (to add the subplot of the away team being trapped on the planet, IIRC).
And I think the sexism goes a little further than just making Kirk a sex object. After Kirk's double has attempted to rape Rand, how is it at all appropriate for Spock to quip that the double "had some interesting qualities" to her?
The biggest stumbling block for the episode, though, is the premise, which is pretty silly. The episode does something interesting with the transporter malfunction set-up, but the set-up just doesn't make sense. It's the opposite from the weirdness that is the end of "Tomorrow Is Yesterday." Instead of combining two masses into one, suddenly one mass is made into two. I'm no scientist, but that does not compute.