It is refreshing that Mac and Khajee never slip into a romantic relationship. They are both teens dealing with adult problems, and they support each other and help each other out without complicating matters. Khajee is a great athlete and shows Mac that he can learn a lot from her. Watching the two of them try to care for Than was heartbreaking and showed that with all of their problems, they were both very mature.
Certainly, there are some things in the book that seem odd. Would Khajee's uncle really be indebted to the promoter to the point where both of their lives were held in thrall to him? Would Mac really have been able to run away, stay close to home, and not have been found by the police? Would he have been able to visit and beat up his father? I believed the motivation for that-- Mac hasn't gotten any counseling for his anger issues (also realistic, since his mother was struggling so much), and when presented with an opportunity to beat up his father, I can see him wanting to do that.
Brawler is an unusual book that adds a sports twist to a book that has a feel similar to spy books, has sympathetic characters in dire circumstances, and that will speak to teen readers who want a book that makes their own lives seem happy in comparison!