Actually, I thought it was brilliant. Technically, it's incredibly well written: really good story arc and very well paced and structured. The use of language is also very strong - it feels like the sort of book that other writers turn round and say "bloody hell, that's well written" (as some of cover quotes suggest).
I also love the story and setting, maybe cos it's not a long way from my era. Well pitched and very reminiscent of the time. Although it is layered on a bit thickly here and there, it's beautifully understated in other parts.
In terms of the characters, okay, both Dex and Emma are caricatures, but they're well written, fully rounded and broadly sympathetic ones and, let's face, they're really a plot device to drive the story at the end of the day. Quite a few of the secondary characters are badly written though, Dex's wife, his friend, Em's boyfriend - they feel really lazy and one dimensional which is bizarre and David Nicholl's can write stunning thumbnail sketches (like the waitress in the restaurant).
So, not without its flaws, but overall a beautifully written book (well, for me anyway!)