I really liked this one! I'm exhausted and I'm sure this will be rambly, but here are my general impressions:
First off, I know he's a bit of a polarizing character, but I fucking LOVE Garth. He's quirky, funny, he's a competent hunter with a good heart, and most of all, he seems well-adjusted and happy. I'm not saying I want to see him front and center all the time, but I think he's a nice addition to the show, and I like what he represents. Plus he killed the tooth fairy! xD
So Dean got possessed. Correct me if I'm wrong, but I think that was a first. I mean, we'd seen all these different versions of Dean before, but I can't remember him ever being taken over by something/someone else. When I first watched the promo, I saw the scene where he points the gun at Sam, but I thought it would be something more along the lines of the siren spell from Sex & Violence. That was a nice surprise. I also thought it was interesting that it sort of mirrored what happened all the way back in Asylum, so I'm adding that to my list of parallels, lol.
Didn't think I'd say this, but I'm enjoying the conflict between Sam and Dean. For one, at least now there's something going on between them, instead of it being just them going through the motions. It's been obvious that Dean resents Sam for not even looking for him, and I suppose I might have liked it better if he hadn't been possessed when he brought it up, but at least now that's out in the open, and so are Sam's feelings on Dean's friendship with Benny. It was a good follow-up to what happened in the end of the last episode, and I like that there was no resolution at the end.
And on the shallow side, I love it when they get physical with each other, so that fight scene was pretty hot. *g*
That said, I'm really having trouble understanding where Sam is coming from. Well, completely anyway, and it's frustrating. I get why Dean is so attached to Benny, even without having the full picture yet, and I get why he's being so hard on Sam, even if I also think he's not trying to see things from Sam's POV at all. I like that we had those flashbacks tonight, because they did shed some light on Sam's mindset during that year and they also added to Amelia's character, but I still don't get why he didn't even try looking for Dean. Besides, I can see why he would be mad over Dean being friends with Benny, generally speaking, but tonight? It may be my shipper goggles, but I thought he actually sounded jealous more than anything, and I think he really has no right. He wasn't there for Dean, and Benny apparently was. Sam being angry because of Dean's double standards when it comes to relationships with supernatural beings is something I can understand, but he's also angry at Dean for being resentful, and that doesn't make sense to me, not yet anyway.
So yeah, I'm again in wait and see mode. In the meantime, I'm having fun with the conflict, because at least they still care about each other enough to fight.