Alternately amusing, exciting, and embarrasing. The effects are pretty impressive, and David Tennant and Freema are both great, although the Doctor's character is beginning to get a bit samey and predictable. And the humour, and the Doctor-Martha bed scene are very good. However, the witches are nothing short of embarrasing, and they are most unconvincing as dangerous villains. Christina Cole, who was brilliant in Hex does a good job with her poor dialogue.
But I can't help thinking this could've been a lot better.