Any novel by John Scalzi is going to be worth reading, and while this one wasn't my favorite of his work, it was certainly an entertaining way to spend a few hours. He does an interesting thing with gender in this novel, and after I figured it out I was fascinated to see it followed through until the end. My biggest quibble with the book is that it seemed to end very abruptly - like it was building to a climax, and then for some reason he just quit writing. It felt a little bit like the two-hour premier of a new series - lots of build-up, and then a bit of an unsatisfying ending to draw people in for the next installment.
That said, even my least-favorite Scalzi is a lot more entertaining than many things, and I will, as always, be early awaiting his next project.