I enjoyed it. The first two parts were superb, but it drifted after that. The first time I saw it Sylv' clowning around in episode 4 was tiresome; but not today.
Clowns are cool in a freaky way. So are circuses. That makes for one amazing setting for a Doctor Who serial.
Sylvester and Sophie were at their usual high standard. Jess Martin looked great and gave a first class performance, as did Captain Cook and the Chief Clown. I liked the Ring Master's introductions.
Great story (though this review is kinda awful)