Actually it is quite hard to write about a good episode, in a rapid response (as ajr said). You can say 'I liked the bit where...' or you make carping remarks about the minor aspects that you can think of criticisms for. Neither very satisfactory. It was a little gentler and less frightening than I was wanting, but this is a kids' show after all. 'Not as horrible as something I just thought of', to quote Life of Brian, but nice to see Children's TV tackling Angst and the meaninglessness of existence. Oh heck, I just have to say 'I liked the bit where...'
I liked the bit where River punched him in the face and I liked the bit where she handcuffed him up/ Donna journeyed through the matrix/ the Doctor sort of grew into himself a bit, being the oncoming storm and so on, excellent.