Sometimes I'm looking for a good, entertaining space opera, and Aristiea fit the bill perfectly. On top of that, it also raised some interesting and deeper questions about loyalty that made it stand above the average whiz-bang interstellar adventure novel.
Above all, it's a well written book, especially on two counts: plot and characterization. I'm always disappointed when I can tell where a book is going to end up after the first couple of pages, but Aristiea defied all my expectations. It plays around some standard sci fi narrative ruts, but never falls into any of them. I was genuinely surprised at the twists and turns of the story, and that made it a fun read.
Second, I thought the characters were exceptionally well drawn. They weren't just cardboard cutouts. They had different ideas and opinions and perspectives, and they were handled with equal measures of sympathy and complexity. It wasn't just righteous good guys against evil bad guys, with no one able to see outside their narrow range. Characters, particularly the main one, actually change and develop. One of the things I liked best about the book was getting to know the core cast of players.
As I said above, the book is also more about blaster fights and space battles. It's also saying something about the nature of allegiance, to friends, to family, and to governments, that seemed both timely and compelling. Again, I enjoyed this theme mostly through the characters' (primarily Maarkean's) development.
Overall, I'd highly recommend this book, both as a fun read and as an exploration of some important issues around loyalty.