The first 80% of the book was an entertaining, easy-to-follow jaunt through the galaxy. There were interesting characters, decision points, and intriguing turns of events. The world building left a lot to the imagination, but not distractingly so. What dragged the whole train off of the rails was the last several chapters. In a universe of unfathomable technology and biology, the character decisions and actions in the final act were the largest obstacle to suspending disbelief and left a real sour taste in my mouth.