The setting of Prague was very atmospheric and I enjoyed the descriptions. The world was interesting and unique with the information was spread out nicely, so it didn't feel like there was a huge info dump at the start like some fantasy books do. At first it actually felt a bit like a contemporary or mystery book, but then as you went on there were more and more mentions of magic. The explanations actually felt a bit sparse for me, but it made sense as Karou didn't know much either and it added to the mysterious atmosphere. It did get a bit more dense by the end, but the stakes were raised and I was invested already so it didn’t matter. The magic system is really interesting, despite being pretty morbid. There isn’t a lot of action but you're constantly trying to put the pieces together and figure out what on earth is going on, so it kept me engaged. 
I love the writing style and I can’t wait to read the rest of the trilogy as well as Strange the Dreamer, and any other Laini Taylor books I can get my hands on. Overall, highly recommend.