I kind of can't believe this was a Buckleming episode. Sure, it wasn't perfect, but I didn't have the problems with it that I usually have when those two pen an episode.
Cons:
Nick's subplot isn't the worst thing in the world, but the fact remains that I'm much less interested in him than I am in the main story. It would have been more interesting, albeit a bit obvious, if Nick had killed his own family, but now we see that he was manipulated by Lucifer into saying "yes," because demons possessed someone and slaughtered his wife and child. It looks like Lucifer's influence on him over time has poisoned his soul and made him evil? I don't know. If this is how Lucifer comes back, then it's a little lame, and it's happening too fast. I'm of two minds, because I don't want a ton of episodes about Nick, but I also don't like how the evil within him is apparently already taking hold. Kind of lame.
I love the stuff with Jack and Dean. I really do. But does it rub anyone else the wrong way that the focus is so much on their relationship? This is yet another example of how every non-Winchester character seems to form a closer bond with Dean than with Sam. Initially, Sam was the one who believed in Jack and wanted to help him. Why isn't he invited along on this father-son bonding trip? Or why don't we at least see a moment where Jack is being sentimental and thankful to Sam and Cas, too? Why just Dean? And for that matter, didn't Mary and Jack get really close when they spent all that time together in the other dimension? Did nobody think to give her a call?