I loved, loved this book as a teen. As an adult I'm a bit more critical--the science is flawed in a lot of places, and it could have used an editor's attention to the numbers given for times, distances, and populations, which frequently change by an order of magnitude from scene to scene--but you know what? It's still a fun book. And sometimes, what I really want isn't something shocking or deep or gorgeously written, but just reasonably paced adventuring fun. This has that in spades. Add some characters who feel like old friends and a picturesque galaxy, and what more could you ask for in vacation reading?
Also, I love the cover, which manages to be both beautiful and one of the more accurate depictions of a specific scene I've ever seen.
I know one thing people complain about is the fact that the book's two separate plot threads never actually connect except by sheer coincidence and thematic context, but that's actually one of the things I appreciate about it. It makes the galaxy feel genuinely big--multiple players with multiple schemes who aren't always even aware of the other--in a way that a lot of science fiction doesn't, to me.