The lush worldbuilding is imaginative and beautiful out of the gate. It was enough to draw me in but not enough to hold my interest. I mean, I kept reading. But I put the book down at about the end of the second act and didn't pick it up again for days, which isn't like me. Part of it is that even though it's a beautifully evoked world it's a seedy story, which isn't my style. Part of it is that the characters aren't that compelling. Their mediocre at best. Part of it is that I listened to Armstrong's “PubDates” podcast with Amie Kaufman a little and Armstrong talks a good bit about the characters and romance (in the episodes I listened to) but then I don't really see that playing out in the story. So it feels like she had these ideas or things she wanted to do or was trying to do but that aren't actually there in the story. At least not yet.
Also writing in present tense third person is an unorthodox choice. I don’t hate it, but I don’t see the point of it either. Still, the writing skill is there enough to make this a decent read. The story has the potential for so much more depth than it achieved. And it was missing something that would pull me in to be immersed in the story, but I’m not sure what. I think maybe emotion. Things are described well enough but I never felt anything, which is maybe what pulls you out of reality into a story. I don’t know. But Nightbirds didn't have it.