I think we've had a couple of pretty solid episodes. Last week's was more of a filler ep, but it was pretty good, mostly because a) YAY CHARLIE, and b) Dean has become a hug monster. I definitely approve.
I thought last night's ep was very interesting too. I know some people are unhappy that Dean didn't have a bigger role to play, but I really enjoyed the Sam-and-Dean scenes -- Dean cooking for Sam, Sam talking about the donkey, the icy bath... it all made me very happy. It was also cool that they focused more on Sam's issues with the trials, and there were some very emotional moments. Poor Sam was so messed up, and I love the idea that the trials are purifying him somehow. That scene totally broke my heart.
I also liked Metatron and how they explained why we had never heard of him before. I was a bit skeptical when the first spoilers about him came out, but I think it all turned out pretty well and I enjoyed their take on the character.
Another thing I liked was how Kevin realized those demons were not the real Sam and Dean. I figured there was something off about them right away in that first scene, but throughout the episode it was interesting to see how close they acted like Sam and Dean, but never quite nailed it, so kudos to Jared and Jensen for that.
As for Castiel, I really enjoyed his moments of badassery and I think there were some interesting developments. Specifically, I'm intrigued by what Naomi said about having wiped his mind over and over, and that he always ends up disobeying his orders. It shifted my take on Castiel in a positive way, because I think that having his tendency to disobey be part of his backstory makes him a more well-rounded character. I feel that this little detail gives his past behavior a whole new spin and makes him seem more independent from the Winchesters in the show's mytharc, and I think that's always a good thing because it makes him less of a plot device. The frequent mindwiping would also explain why he often seemed more clueless about humanity than the other angels, so it all tied in nicely for me.
All in all, I'm definitely excited for the final episodes. I think this season has been kind of messy, but I see the potential for a solid ending, so I'm feeling pretty positive. :)