NOTE: I was given an ARC of this book from NetGalley in exchange for an honest review. 
 This book is awesome -- it's smart and challenging and boundary breaking and funny, as you'd expect from Courtney Milan. She's always been committed to writing smart books about smart, interesting people and this book gets pretty geeky, but it's all there for a reason. The theoretical physics and the apocalyptic scenarios and the math and laser jokes are key to the connection between Maria and Jay. Then as romances get more diverse people are going to have to figure out how to write about a wider range of experiences and backgrounds and Milan is amazing at that too. She neither backs away from difference nor does she make a big deal about it. There is a really diverse set of characters here-- across ethnicities, class, sexualities and everything in between-- and it's all managed in a matter of fact way (maybe that shouldn't be surprising or remarkable, but it is). The focus is always on the psychological complexity of the characters (who make mistakes... BIG mistakes...but Milan lets them recover from them) and the emotional complexity of their romance. Personally, Maria and Jay don't do it for me as a couple as much as Blake and Tina (I love that their relationship keeps developing in this book. They aren't abandoned to their HEA) because it takes them so much of the book to get together (they do earn it). But the book as a book may be better than Trade Me -- just because it's more ambitious and challenging. Absolutely 100% five stars and highly recommended!