I started this, intending to read one chapter before bed. And instead I read it in a sitting. (No, in case you were wondering, I never learn.) I think it's safe to assume it's a fast read, and action-packed.
I don't really feel like giving a synopsis, since there's already one right on the top of the page. Though I should point out that whoever is writing those synopsisis seems to be giving the impression that the point of the book is the main character finding out War is BAAADDD. I respectfully submit that that is not the point of the book, since it goes over personhood and loyalty and the necessity of choice and the ethical issues of treason and being the people who do the dirty work. BUT ANYWAYS.
Main differences from Old Man's War are; a different main character, with a different sense of humour, and less people being eaten, more kids dying.