A few things, after having watched the episode finally.
It was better than the first two, which is nice.
After a weak start, the writing got a little bit better with each episode.
Crowley is the best part of the show, and I like how he finds justifications for himself why he keeps Castiel around, and why he cares for Dean (even if he says he doesn't).
I liked the stalking of Sam through Dean in the latter part of the episode.
Ackles is actually good at playing menacing, which is all the more reason to wish he would have remained demon.
That said, I'm not buying that he is truly human again. This went too neatly in the end, too fast and without a hitch.
Something was amiss.
Also, was that Abaddon at the end?