In short, this book was entertaining. If you're looking for a sharp wit, straight-forward humor, and a good laugh, this is perfect.
An immensely enjoyable tale with a clever point of view. Like Star Trek? Ever wonder what it must feel like to be one of the disposable cast of extras, seemingly killed off each episode for ratings? Then you'll enjoy this fun read. Only critique I would give is that the author holds dogmatically to Stephen Kings "thou shalt only use 'said' for dialog tags", so the audio book version gets confusing at times, but if you can ignore that, you'll love it!
Scalzi is channeling Heinlein in this enjoyable space marines epic which is built around the twist of sending old, rather than young, folks to war. I'll have to check out the sequel some time.