I agree with Wrath that it was probably the worst episode of the past two seasons. Giving every character (except Betty) a cute happy ending didn't feel like Mad Men at all. To me there was only one way this show could have ended: Don alone and miserable, luck run out, full of regret over the horrible way he's treated people over the last decade. The show just doesn't make sense otherwise.
Him finding peace at a spiritual retreat just doesn't hold any weight to it because he's always running off and doing weird things. He was racing cars earlier in the episode. He'll likely be doing something else is another week. The hug scene seemed like it was supposed to have some weight to it but missed its mark with me. Certainly no Kodak Carousel moment.
I also agree with pilonv that Peggy/Stan felt extremely rushed and Wrath that it was corny. The rushing up to her while she's still on the phone felt right out of a rom com.
I did like how we got to see a little bit of Don as a drunk, but there probably should have been more. In my opinion all the best episodes ended with the characters being sad and lonely despite all the success they were having in their lives. So this ending just felt so off to me.
All in all, superb show. I can't think of any television I've enjoyed more over the past seven years. But what a weak ending. I guess Matt Weiner just can't close. I'm not mad at him, though. The overall package has been amazing.
Edit: Just read some pieces on the finale and realize that by being so focused on how the finale wasn't what I wanted it to be, I completely missed the possibility Don came up with the Coke ad.
I like the ending a little better now. I kinda love the ending now. Don gonna Don.
