I saw the movie a few years ago, and so I read this book on a whim. Its very different to the movie. The book is interesting, although it does have a tendency to slide into rants about the moral responsibilities which come with having an electoral franchise. The book is also very pro military in its stance, although that’s fair enough (an author without an opinion would be a boring author).
Overall, I thought this book was an enjoyable read.
Update 2013: I last read this book almost exactly four years ago. Its still a good read, and I didn’t find it as ranty as last time. I do think this is a better story than the movie, as it has more depth. Overall a good read, if not a particularly deep one.