What can I say, but that I'm rather surprised! 
 This book turned around all my expectations. Granted, I had only read the first Grisha book so I didn't have a lot to go on, but I started this with a bit of a bump because I'm fond of Heist novels. 
 And I got exactly what I expected! Solid plot, interesting characters, flavorful prose with mixed angst, greed, and let's never forgive that never-ending hope! 
 If this is a continuing trend, and I assume it is, since I've read 9 novels in the last 2 years, or ten including this one, that mixes magic and thievery, then at least I haven't gotten tired of the trope yet. Maybe someone else might have, but this is a very decent and steady mix in the field. 
 It already has a lot going for it for those following this author's Grisha series, of course. People already know and love the worldbuilding. The setting is set and cast. All that's left is a deep diving into the characters and the adventure, and that just happens to be what I was in the mood for. Although, honestly, there's no need to read the Grisha novels in order to enjoy this one. Everything is pretty self-explanatory. They may add to your understanding or provide the backstory you feel you might be missing, but I didn't feel any lack. 
 In fact, I think I'll go ahead and return to books 2 and 3 joyfully, precisely because I have a better understanding about where the series will head from the spoilers I may have gleamed from this one, but it's more like it whetted my appetite than became anything like a real spoiler. 
 I feel like I must do a little comparison between this and a few of the other Fantasy/Heist novels I've read recently, especially since they're all coming out so close upon each other. A huge nod must be made to The Lies of Locke Lamora and its two sequels, as well as to The Palace Job and its two sequels. To put things in perspective, some, Six of Crows uses costumes and time jumps (flashbacks or however you want to call them) to good effect, but doesn't take over the dialogue as much as in The Lies of Locke Lamora. It also has more magic. The Six of Crows is definitely not as tongue-in-cheek or as plainly funny and trope-poking as The Palace Job, nor does it have quite the facile turn of phrase or pacing during the battles. But Six of Crows definitely has the overall advantage of solid flowing pacing that never lets the reader go through the entire read. 
 In other words, it was a serious, magic-filled escapade full of dark heroes and horrible odds. Isn't that what we all like? I hope so. I'd love to read more of these. 
 One other thing. I'm a complete and utter sucker for that whole thing going on between Nina and Matthias. There sure is a lot of fire in there. :) It was almost funny to watch how much they "hated" one another. 
 Good fun! I'm happy to see something insanely popular actually deserving it, again. :)