As strange as it probably sounds, in the past few seasons I've generally been able to rate an episode based on how much I end up "MSTing" it, or making wisecracks back at the screen. And for this one, I really didn't have the urge to do so.
As for Gabriel, I know there was a lot of controversy over the retconning of the Trickster back in season 5. And I see they were trying to explain it away here with the whole thing about Loki helping out Gabriel by letting him act like him and look like him, but then he held Gabriel responsible for his father getting killed ... the whole thing kind of makes my head spin, lol. Maybe upon rewatching I'll be able to form more of an opinion.
It was kinda cool though to see Richard playing both parts and I did like that pouty face and little "aww" of his before he killed Loki.
I did find it odd though how Dean just disappeared at first and ended up going after Loki himself and I was glad Sam confronted him about that later. Just like his other behavior of late he explains it away as wanting to keep Sam safe whereas he doesn't care what happens to himself. I loved Sam telling him that they'll do this together and that if they die, they'll die together (so powerful and almost makes you want to cry hearing that...wow I can't believe it's been so long since I felt that way).
Just a quick few words on Jack, Mary etc in the other world: Sucks that Kevin blew himself up and nearly killed them all in the process. Kind of a tragic character. I felt bad for Jack and how he blamed himself. I really liked his interaction with Mary.