I guessed the denouement. I knew there had to be some reason for introducing that parallel universe and by the end (or rather, just before the end) I'd worked out what it was. I've liked the story arc in this season.
And even though I knew how it was going to pan out, I liked the way it was done. It could have been slushy and unconvincing and groan-making and it wasn't. Russell T Davies is a damn good writer.
I'll miss Billie Piper. She's marvellous.