Firstly, I would like to make it clear that I enjoyed "Working for the Devil" enormously. Necromancy AND plasma rifles;what more could you ask for? The pace is relentless and it was basically a 2 sitting book; it would have been 1 but other people sometimes expect me to do stuff. Many aspects of the world Saintcrow has created are genuinely original and she succeeds in evoking a thoroughly threatening atmosphere. Tierce Japhrimel is also the coolest sidekick ever. However, if you are looking for writing of, say, Jim Butcher's standard you will be disappointed. A lot of information about the environment is handed out in ham-fisted info-dumps. Character development is pretty much restricted to Dante, although, given how monumentally self-centred the protaganist is, this might be a deliberate device to illustrate her world-view. The ending is rushed and has something of a deus ex machina quality to it with previous impossible things turning out to be straightforward after all. Finally, the actual words could have done with some aggressive line-editing. Most of the technical faults are really evidence of how little respect the publisher has for the readership of this kind of urban fantasy and could have been easily fixed.
More interesting is Dante Valentine herself. It has been noted by other reviewers that she is an extraordinarily self-pitying whiner and I won't go into this except to agree. What no-one else seems to have commented on is that she appears to be a psychopath. While she endlessly complains about the bad things that happen to her, she never seems to consider the morality of her own actions for a second. The only ethics she seems to recognise are the concept of a contract and the idea of blood-vengeance. She reminds me of "Angel Eyes" in "The Good, The Bad and The Ugly." I've nothing against anti-heros, I grew up on Elric, but Dante's apparently total lack of self-knowledge is a missed opportunity. Perhaps this will be addressed in later books.