I gotta say, it was a pretty good ending. I really love the dynamics of these characters and the story that Bardugo has to tell. Also, her writing is absolutely phenomenal. It's something so entrancing compared to that of the Grisha trilogy. I can't believe how much her style has changed into something full of grandeur and magicalness. It's awesome. 
 Six of Crows was fantastic. An utterly epic novel full of twists and turns right to the end of the book where it didn't stop--and then including that with the backstories of the characters, well, you've got yourself a fantastic book! 
 However, Crooked Kingdom was... lacking the epic scope of a finale. There wasn't much of a fight, a war, so much as a brawl--and it focused more on justice and regaining what the crew already had rather than taking back at the enemies. I don't like it when the endings of series are like that. I love it when the last instalment features life-altering events that change the whole world of the book rather than just... meaningless blabber. 
 Now, that isn't to say that CK didn't change anything. It changed heaps. 
 The world changed, the characters, the plot, the society, Ketterdam and more. But... I just needed a little bit more epicness into this finale and it would've gotten all those 5 stars. 
 There needs to be another series in this world, though. I can see it happening. 
 *whispers* But I'll always love Kaz Brekker.