I really liked this episode, maybe being a Buffy fan helped a little in that aspect. Firstly, James Masters looks amazing, he has aged very well.
The episode had a fair bit of humour to it, I laughed several times. It seemed like a more light hearted episode.
Dean and Sam entered the house and just starting chanting to kill the witches, which seemed very clumsy. hence the score 9/10. I think in order to receive a 10/10, maybe they could have explained why the decided to spare the witches and planned or showed a little more research into the withces. I mean were the witches evil for over 800 years and should have been killed? Not enough background into the characters.
I especially liked the end, it was a nice surprise element. I was expecting someone else to be reasonable, but when you find out who it was, it was great. It also had those excellent one liners Buffy was famous for.