I watched this one a few days ago. While it's always at the top of the list of "all time favorite episodes" whenever a survey comes up...well, I just don't rate it that highly. There's something about it that just seems off. I've read Ellison's draft (one of them anyway) and I'm neither here nor there with his either. A few things keep me from loving this one.
1) Sense of time and place: 1930 never feels real. I mean, sure, the trappings are there, but thanks to the limitations of budget and time, it always feels artificial. This is, what, the third time we're on the Mayberry set? There were no matte paintings to put skyscrapers in the background over the "too small for that part of Manhattan" buildings, very few interactions that make me feel like they're trapped back in time. Ellison's version makes it clearer that Spock's life expectancy in such an invironment is limited if he's discovered. Lip service is paid toward the depression era strife, no real effort is spent to actually truly depict it other than bums in the mission. I know that's not the point of the episode, but their surroundings feel no more real to me than the O.K. Corral did two years later. Even The Time Tunnel was more convincing. And we have no idea how long Kirk and Spock are waiting for McCoy. Weeks? Months?
2) The relationship with Edith: I'm not sold on her. She spouts very unlikely speeches that are a little on the nose, just to make it clear that Kirk would take notice of her. Their romance doesn't feel grounded in anything other than she's a futurist. Their relationship is remote. Shatner is charming and does his best to convey Kirk's longing for her, but Joan Collins doesn't sell it the same way. Why does she assume Spock calls Kirk "captain" when we never hear him address him that way in her presence? It obviously happened since Kirk doesn't question it, but we needed to see it. She is this way because she needs to be for the plot, but she doesn't feel like a person. She's a chess piece. I feel as if this episode is cheated by being a single part installment. Had this been a two part episode closing out the season, more time could have been spent developing Edith as a character. She really isn't one. Whatever I feel for her is based entirely on Shatner's performance. I feel no sadless at all for Edith. Frankly, whatever importence she carried in Kirk's life is created entirely by stories written well after the series ended. Writers have been telling us for years that she is the one great love in Kirk's life. But other episodes would show us a few more. Hell, I actually like Miramanee more as we got to see them grow together over the months.
I realize any dozen of you will come back and tell me why I'm wrong.

But like a number of episodes in the late first season, I find this one to be not as amazing as most people feel. The shitty ADR doesn't help. The overdubbing of Shatner and Nimoy in the Guardian scenes is partifcularly sloppy.
Above average, but that's about all it is for me.