4.5 stars, really.
This tale of a magical, modern-day London and a coming apocalypse is both clever and thoughtful. I loved it. However, while it delighted me, I can see that it probably has a limited audience. It's rife with pop culture references. Pop culture references in literature usually annoy me, however, in this book they had what I can only imagine is the usual intended effect: the feeling that "he's writing this just for ME!" Tintin and Star Trek, Peter Sotos and G.G. Allin, Ursula LeGuin and Michael Moorcock... if you've got no idea about any of that, you're going to miss a lot. I also fit into the sub-group of readers who are highly cynical of religion, but fascinated by the operations of belief systems. I love the idea of the interstitial, of hidden streets and occult knowledge. Maps. Arcane and ancient relics. Books. Magic. Science. Oceans. etc. ME!
He's aiming at a specific age group, and a particular cultural milieu to comment on, and it's on-target.
It's quite different from most of Mieville's other books, more like Un Lun Dun than anything. At times, it reminded me quite a lot of Neil Gaiman (think 'Neverwhere')- but a much nastier, more disturbing Gaiman; one who pulls no punches.
Addendum: It's taken me a bit to put my finger on this. Something Mieville does astoundingly well in this book is something I'm not sure I've ever really seen done well before. You know those nightmares/dreams where something OUGHT to be splendiforous and magnificent - but yet it's not? It's almost wonderful - but something isn't quite right, making it either banal, terrifying, or just wrong? The protagonist, Billy, has one of those dreams in the book, and the plot of the book follows that concept as well. It's effectively disturbing. I feel I'm left with the same feeling that one of those dreams gives me.