Before looking at the episodes themselves, I just want to admire the appateaser from the SPN editing crew:
It does such a good job of creating suspense without detracting at all from the actual viewing experience--no real spoilers here. And that's quite pleasant to encounter in today's world of "here, let me condense all the best parts of the movie/episode into a trailer so you can guess the entire story without even watching it". None of that from the SPN editing crew.
Who We Are
Wasn't this a great episode? I didn't expect to like it so much--it's a season arc episode, and I tend to be ambivalent over those, but everything fell into place so nicely (and Dean finally got to use the grenade launcher) that it was thoroughly enjoyable. And beginning, middle, and end were solidly Sam-and-Dean, so that automatically gets it bonus points.
This is one of those episodes where I'm not going to bother listing off things that I loved because pretty much every other scene could just get quoted/screen capped in its entirely. A+, Mr. Berens. A+. (Feel free to squee about stuff in the comments :D )
All Along the Watchtower
Given the way they ended it with Lucifer in 12.21, in retrospect this episode really shouldn't have come a surprise. But I made the mistake of talking with some people about it before I had a chance to watch it for myself, and their reaction spoiled mine a bit because I went into it with the wrong frame of mind. However, again, despite [spoiler]all the deaths/dimensional exiles it was a surprisingly funny episode. The whole thing felt almost more screwball than apocalyptic, which was kind of refreshing. A number of scenes had me outright laughing, which is definitely a first for a finale. And the way they used [spoiler]the alternate dimension as a way to sort of address some of the stuff Dean said to Mary in the 12.22 was pretty clever. I'm curious to see what (if anything) they'll do with it next season. The writers really did give themselves the ability to take s13 in just about any direction they choose, and it's going to be fun seeing out where they go with it.