Three books into the series now (plus one short story), and I have to be honest: I love the concept, I'm disappointed in the execution.
The concept, for those just tuning in: After the War in Heaven and the banishing of those who followed Lucifer in revolt against God, the angel Remiel of the Seraphim Host decided to quit Heaven and dwell on Earth. Eventually, he decided to hide his divine nature in a human guise, and settled into the role of Remy Chandler, a Boston private detective. He fell in love with a mortal woman named Madeline, revealed his true nature to her, and they married. Unwilling to have children that would turn out "unnatural" due to the blend of human and angelic nature, they adopted a dog named Marlowe. Remy also revealed his true nature to a dying cop named Steven Mulvehill, who became one of his two closest friends, the other being a former guardian angel named Francis who had originally followed Lucifer but repented before the War was over and was given penance by God: stand guard over the door to Hell.
All of this back-story happens before the first book in the series, and is sprinkled liberally between the first two books in the series. The first two books were approached as somewhat from Remy's point of view -- not first person narrative, but everything definitely filtered (except for one scene in the first book) through the perspective of knowing only what Remy would know, when he would know it. The first two books were also heavy on the "series set-up" angle: the first book introducing Remy and pitting him literally against the end of the world; the second showing how that near-miss of an apocalypse has set the supernatural world of angels and demons into an agitated kind of motion.
Book three is the first in the series that seems to be more about a case than about the political machinations of Heaven and Hell (although, of course, there is a connection, and a set-up for something that will probably pay off in a big way later should the series last long enough). It's also the first to feature a main bad guy only peripherally associated with Judeo-Christian beliefs: the old god Dagon. There's also a subplot about Samson and Delilah and what they're doing now (no surprise they're immortal; in the one Remy Chandler short story, we found that Noah was still alive too). The Samson and Delilah plot, and the revival of Dagon, come together with the case Remy is currently working on: locating a missing six year old girl named Zoe (who is more than she seems) and the father who stole her away. Those three plots are enough to propel the book, and Sniegoski rightly leaves mentions of Heaven and Hell to a minimum. This is also the first book not told completely through Remy's perspective: chapters (and eventually, scenes within chapters) bounce between Remy, Delilah, Dagon, Zoe's father and mother, and several other supporting characters.
On the upside: 1) the three plots are interesting, and while the way they come together is not really shocking they at least fit together sensibly; 2) Sniegoski finds a somewhat trite but still workable way to keep the late Madeline as an active presence in Remy's life; 3) we get to see more of how the Biblical world is still extant in the modern world (the aforementioned blind Samson and near-demonic Delilah, still both paying some form of penance for the mistakes they made in Biblical times); 4) with this particular plot there is almost no way Sniegoski could have kept things only in Remy's POV, and the change in style makes the third book feel a little fresher (sort of like Jim Butcher writing the novella "Back-up" from Thomas Wraith's POV instead of Harry Dresden's); 5) the scenes between Remy and Marlowe are possibly the best-written scenes in the book.
On the downside: 1) Sniegoski's style is still choppy to the extreme, highly repetitive (not just from scene to scene, but characters repeating each other in the same scene). While he keeps the references to previous books appropriately brief, he has a tendency to repeat information from this story in places that felt out of place, or made it feel like he needed one more good edit; 2) what should be an excellent supporting cast is once again largely relegated to the background -- Madeline is dead, and still gets more screen-time than any of the living recurring characters. The bits where Remy and Mulvehill drink together are fun, but Mulvehill needs more to do than that if we're going to maintain interest in him; 3) with all the repetition of information, there's still a decided lack of sensory detail and what is there feels largely cliched except for a few nice turns of phrase -- Sniegoski's strong point is in the dialogue more than the description; 4) the scenes between Remy and his dog are possibly the best-written scenes in the book.
I really, really want to like this series. The concept is a strong one; the characters have great potential. But so far the potential is not realized, and the lack of immediacy even in the fight scenes made the book disappointing for me.