1. The opening argument. Dean's face and body-language, calling Mary by her name instead of "Mom" in reaction to her presuming upon their mother/son relationship. The way that Sam and Dean function as a seamless unit together.
2. Getting to see a potential case get vetted and discarded--a fun glimpse into a side of things we don't usually see.
3. Sam asking in Dean wants to talk about Mary, Dean saying "no" and then five seconds later talking about Mary.
4. All the parallels that can be drawn from this episode: Mary's vision for the boys matching John's from season 1; Sam acting as mediator between Dean and Mary, just as Dean once acted as one between Sam and John; Mr. Ketch bargaining his way in with whiskey just as Dean once did with Rufus; echoes of the Campbell's approach to hunting in the BMoL compound and Mr. Ketch's willingness to torturing the vampire who was left behind (also--in how the vampires just plowed into the compound under the direction of their alpha, as the shapeshifter alpha did to the Campbells)--heck, even the t-shirt worn by the turncoat hunter had the logo of the place Benny worked at, back in "Citizen Fang".
5. Dean being all stonefaced at Mr. Ketch during the whiskey-drinking.
6. Sam refusing to sit for the raid briefing.
7. Mary desperately wanting to reconnect, and Dean relenting at the end--without condoning her choice.
8. Dean getting the info needed by stopping Mr. Ketch and offering the vampire a clean death--showing that he, unlike Mr. Ketch, doesn't need a leash and someone to hold it.
9. The scene between Sam and the alpha vampire--they stood nearly as equals, which allowed for some nice back-and-forth.
10. This whole episode functional nearly as an outsider POV on the episode and what it gave us was a Sam and Dean who are flawed mortals, but also in a different class than the BMoL and even Mary. Sam had better skills, better intell, more experience. Dean showed himself to be more effective than Mr. Ketch--and entirely his own master.
11. Mr. Ketch and Mick are proving to be much more interesting and nuanced than I expected from their introductions. I hope the BMoL don't stay around for too long, as they could very easily break the established premise of the show, but I'm definitely enjoying them while they're around.
12. I kind of stupidly love that we now have yet another instance of Sam and Dean leaving utterly uninformative notes to each other. It's like an ongoing unofficial content to see who can be the most laconic.