This book had a great deal going for it; Eric Flint clearly did a lot of research on military strategy, history, and both early modern and modern weapons. This is evident throughout the novel, and helped make his novel a superior and interesting work of fiction. However, his research was not the only thing that made this book wonderful.
One problem I have with a lot of science fiction and fantasy novels written by men is a lack of credible female characters. Throughout the story, there were several wonderful female characters, none of whom were the same. One woman was a nurse, another a polyglot and diplomat, and another was an olympic biathlon participant who became one hell of a sniper. They were respected by their male peers as equals, even those who were non-Americans from the past.
Overall, I would recommend this novel, as it is well worth the necessary time to read it. It does drag in a couple places, but that is a pretty small complaint in the grand scheme of things.