I will read anything Cooney writes and I would listen to her read the telephone book.
This book is...imagine if Cat Valente wrote Gideon the Ninth. 
Cooney is extravagant as a writer; every page feels like an avalanche of imagery and the words themselves flow and dance and gambol across the sentences. If you like sparseness and cleanness, she's probably not the author for you. But if you've ever looked at the most decadent cupcake in the store and thought "yes, that one, because I *can*" then Cooney is perfect for you.
Also, you know, there's the death and the necromancy and the found family and the absurdly baroque magic and, just, entirely my thing.