So, I've just watched it and it was amazing.
Some great one liners in there. Caskett were great, really loved the blending of the two scenes, with Castle and Martha on one side and Beckett and Dorn on the other.
It's so weird seeing Dorn play this role. It's so geekalicious, but weird. He needs his forehead back, and some weapons. IT'S A GOOD DAY TO DIE!
So glad the kiss wasn't as bad as expected, though it was really cute seeing Beckett so annoyed over it all. You could tell she was really having a hard time keeping control. Kind of annoyed they didn't show us the answer to the question, but understandable really. That'd be telling us too much too soon. Was annoyed Castle didn't tell her the real reason he and the lady didn't go out, but he probably doesn't want to scare Beckett away, but you could see he was happy not having to choose.
I feel so bad for Beckett. If she's not careful, she might lose Castle (Esposito had some choice lines this time as well) all because she's not able to handle her feelings for him. I like that they're showing that.
Martha is now becoming Castle's Dorn (the psychiatrist as we don't have a name for him yet).