None of the major elements of this series are new. Vampirism caused by a virus (been there), healing quickly so not worried about being injured (done that), clan wars between different undead factions (seen it), depravity and a disregard for regular standards of human decency whilst still showing signs of a conscience (bought the T-shirt for that one).
But despite these familiar ingredients Huston's books feel fresh. That's possibly because he puts a bit of twist on all of them. Joe Pitt is callous one minute, whilst agonising on whether he should infect his human girlfriend, making her a vampire to save her from dying of AIDS.
The clan wars are spun by introducing a family of ultra-religious Jewish vampires -intent on pursuing their vampiric goals whilst still obeying Jewish law. Throw in a group of misfits who have decided that the best thing to do with vampirism is to stage a freak show. The only difference is that the blood and gore are real, rather than staged, with the performers relying upon fast healing powers to be able to perform the following night.
This is real noir stuff. It has the feel of a typical old-school pulp crime story, right down to the cynical first person narrative. Joe's character matches almost exactly the downtrodden Private Eye. He isn't averse to violence, but equally he is not a guaranteed winner in his fights.
His "job" is to be an enforcer type for "The Society", one of the vampire clans on Manhattan Island. It's not a position he cares overly for, nor one he is that comfortable with. He'd prefer to make his own way, but knows that being independent or rogue would ensure a very short life. The result of this is he is not the most diligent of enforcer. See him backed into a corner and the Society's needs will be the last consideration in his attempt to escape it.
Huston's language is strong but it fits. His vampires are immoral so why would they worry about profanity. His stories are brutal, extremely violent in a casual way. Whereas a lot of modern vampire stories are horror-lite, providing a kind of diet-terror, this is the full-fat, hi-salt variety. These are not books you would want to give your teenage niece who enjoyed Buffy the Vampire Slayer.
Bloody, violent and relentless. What more do you want?