The page count is due to small text. I'm sure if it were printed in a more normal sized font, it would have been 400 or better.
So the H - Jack Geary, promoted posthumously to captain 'cept that he wasn't dead yet, and known throughout the galaxy as the legendary Captain "Black Jack" Geary who'd done some heroic deeds that got him killed except that he didn't and he wasn't, was found in deep hibernation in his escape pod some 100 years after a surprise attack that got his fleet destroyed. And he finds himself in position of commanding a fleet in an escape from an ill-advised invasion gone horribly wrong. Various people are either in awe of him due to his reputation, or dislike him strongly, possibly due to feeling like they can never compare.
It was...slow. We spend a lot of time either in the H's head, or in some sort of discussion, or plotting or scheming or... And at the end of the book, they still aren't home. No idea how many jumps (space travel and other things are both confusing and seemingly unnecessarily complicated - do we really need to know that ships suddenly appearing on the radar showed up hours ago and light just got there?), or how many more books. I guess I'd have to find the rest of the series and read the last page of a few to figure that one out.
I *really* don't like cliffhangers.