I enjoyed the Grisha trilogy, but this book completely blew me away. It had none of the weaknesses that I complained about from the Grisha books. Because, let's be honest, the main heroine of the trilogy, Alina, was sometimes annoying. Mal, one of her three possible love-interests, was a whiny-mcwhiney-pants who needed to man the fuck right up.
Not here. Every single character in this book was awesome, and the chemistry between the six members of what started out as a connected group of losers and ended up as a rag tag band of heroes was amazing. If the characters from The Breakfast Club turned super bad ass and staged a prison break in the Arctic Circle, you'd get this book.
Leigh Bardugo's world is fresh and engaging. There is a swashbuckling appeal to the plot, and she is at her best when she is swashbuckle mode (my favorite character in the last trilogy was Prince Nikolai, who was a pirate).
This is also a smaller story than the traditional high fantasy. There's no chosen one, no grand battle between good and evil to save the world. It's a tale of a heist, but within the context of the story, Bardugo incorporates meaty issues like slavery and commerce, jingoism and hypocrisy.
This book fits into to the universe in the aftermath of the Ravka civil war, but you can definitely read it without having read the Grisha trilogy first. The trilogy will give readers a better grounding in the world, and in the magic in the world, but it should be possible to jump in with both feet. If the original trilogy doesn't appeal, give this one a try.