The Dresden x-ref and Gaiman link (and my usual faith in forum reco's, thanx muchly people!) were enough for me to pick up the first and second books, THE DEVIL YOU KNOW and VISCIOUS CIRCLE.
I like.
Let's get the obvious out of the way. Similarities (first persona narrator, urban fantasy, sort-of-detective magic using protagonist) aside, this is not Jim Butcher's Dresden. The magic is less overt, the protagonist is less powerful, the world is just a bit more 'real' and grounded, at least so far in the series.
Also, Carey is thoroughly British, and the series is set in London, so the slang and settings and cultural refs may be a bit odd to a north american reader.
That said, Carey has created a believable world, with some interesting things in the background (the dead just started rising with frequency about a decade ago, no one is sure why tho there are theories, none of them pleasant). His supporting cast (by example, Castor's possessed best friend) are good additions to the story without stealing the show, and the stories move along at a decent pace (tho far from the breakneck pace Butcher usually sets, when things get crazy, they do get crazy and Carey writes action very well from the pespective of mere mortal trying hard not to die while supernatural thingies are fighting around him).
If you're an urban fantasy fan, this is worth a look. It's not 'fake sick and read it in a day' fantasy, but it is fun and while i'm not adding Carey to my 'buy in hardback asap' list anytime soon, i'll cheerfully pick up the mmpbs.
one further note for discussion if you've read the series...
SPOILERS SPOILERS FELIX CASTOR SPOILERS SPOILERS WILL
POSSESS YOUR CORPSE AND MIND FUCK IT WITH A
SPOILERS FUCKING SHOVEL SPOILERS DO NOT FUCKING SPOILERS
READ THIS SPOILERS I SWEAR SPOILERS LAST CHANCE DIE ZOMBIE
SCUM DIE SPOILERS
- Abyss, will never trust old buildings in London...