I found this duology the perfect brain candy -- zippy dialogue, light science fiction, a fun detective mystery with a light helping of commentary on privilege and other modern social issues. Head On lacks some of the zing of Lock In, because it is a return to the same world, but I thought it still really had a lot of fun elements. And I liked the way the book explored what happens when a space (or sport) is built for a disadvantaged community and then commercialized and co-opted more broadly.