Four words: Doctor Who does Shadowrun.
I used to play Shadowrun - I have particularly fond memories of Fawn, my shaman - and while I never really got into cyberpunk novels, I know it when I see it. The only thing this is missing is the actual dragons-bursting-through-and-metahumans-evolving. You have young, stupid street samurai, netrunners, arcologies, a dystopian future with vastly poisoned Earth, harvesting of body parts, the US broken up into smaller sections... it's really amazing.
I talk a lot about Ace in this blog, and her characterization bothers me the most. The Doctor, eh, we've seen authors forget the "never cruel" part before. But I don't know how we get from the Ace of Timewyrm: Revelation - or even from the previous book - to this Ace. We have gone from a kid who happens to like blowing stuff up to someone who is perfectly comfortable dealing with Kurdish terrorists in one book, and I don't get it. Characters need to grow and change, but this is ridiculous. Cartmel needed a street samurai to contrast against others characters, and so he stuck Ace in that role. It doesn't progress naturally, and I can't get used to it.
The scene with Justine and Ace doesn't wash, either. Ace has met someone who refers to the Doctor as "Merlin." She's seen demons. The whole Doctor-as-sorcerer thing shouldn't unsettle her at all: she should be able to understand that for some people, that's just their paradigm. After everything that's happened, it's Justine that throws her? Again, I don't get it.
I guess I expected more from someone who actually worked as a script editor for the series. He seems to have willfully, even gleefully disregarded things that happened on his own watch. While I'm all about "Doctor Who doesn't really have a canon," this is a bit too far for me to enjoy.