Such a great conclusion! Much longer than the other books, which put a bit of a dampener on my blitz of the series, but definitely a super satisfying conclusion. Also loved that we had another female friendship added to the series - not just Cinder and Iko, but also Scarlet and Winter in this one, who I really loved together. Scarlet had a lot more personality as a result of this gorgeous relationship, so I liked her a lot more here. All the characters just make me so happy. 
 However, one thing that became incredibly apparent in this novel was that Meyer hadn't really thought through the world building, especially with the Lunar powers, how the cities and towns were actually constructed on the moon (i.e. how do they survive??), what was going on with the gene splicing things, and how Lunars ended up so different from people on Earth. I kept expecting things to become clearer as the book went on, particularly as it is so large, but it kept getting put off or 'explained' in ways that either didn't explain anything at all or were massively internally inconsistent. This goes for the whole series as a result, as I kept waiting for these answers that never came. 
 (view spoiler)[I loved how everyone got their happy ending BUT AT THE SAME TIME I also loved that the book was still so raw and real about war, insanity and the misery of being controlled by others. A+ for realism and also yay for cute scenes at the end - it was a nice balance between the Suzanne Collins school of feeling miserable at a series conclusion and the Stephenie Meyer lalaland of "everyone survives!". Still not perfect - I feel like Brandon Sanderson or even Rowling are better examples of how to write a satisfying ending - but it fit the tone of this series (i.e. light, fun, heisty, with a bit of war and political drama on the side). (hide spoiler)] 
 Second read: omg everything is so hetero what. Otherwise as above!