Wow, an author that I'd been delaying getting "into" who actually lives up to the hype. What a book - it had everything I could ask for. It was one of the most approachable sci-fi books I've read, more in the vein of Ender's Game or Wool, where the people and the conflicts are the focal point, less than the technology and hard science. Call me a non-nerd, but "hard" sci-fi just doesn't do it for me. Old Man's War, on the other hand, DOES it for me.
This book is well-written, engaging, endearing, and entertaining. The characters generally have a "real" feel to them (despite, well, not being "real"), and are entertaining and funny (I repeatedly lost it over what they named their Brain Pals). The plot and setting are unique, something crazy and feasible and fun. I eagerly look forward to more books in this series, as well as more of Scalzi's work.