It will come as no surprise that I absolutely devoured this book. Loved every single page of it.
SJM is excellent. I will read everything she ever writes. And this, being her only standalone novel to date, was such a delight! 
I adored this reimagining of Catwoman and Batwing -- Selina and Luke have my whole heart. Their story is action-packed, thrilling, full of mystery, deceit, and so much heart. 

Selina --
The perfect boss babe main character. This is her story, that's for sure. She's strong, dedicated to her cause, loyal to a fault, and loves with her whole being. 
Luke -- 
The tortured hero. He's conflicted, devoted to his loved ones and to Gotham, and slightly cocky -- which gets him into a bit more trouble than he's ready for at first. But man, we love him. 

As always, SJM's storytelling is masterful, original, compelling, and keeps you guessing at every turn. 
Epic. Nerdy. Perfect.

I liked that this one included Poison Ivy and Harley Quinn. Batwing/Lucius Fox was interesting and, in the context of this story, making him the love interest kind of made more sense than Bruce Wayne.
The plot felt like it could've been stronger and more cohesive . Some things are mentioned, but not explained well.