OK. So.

It's well-written and has some fantastic world-building and really, really interesting ideas.

It is also rife with personal tragedy. I stuck it out in the hope that all the painful ironies, cringe-inducing misunderstandings and heart-wrenching sacrifices would all be worth it, in the end, when the galaxy was saved in an epic battle.

But the ending was ambiguous and unsatisfying. Two main characters die; meanwhile, of the three alien bad guys, one is killed "off-screen" (you don't find out for sure that he died until later) and two get away scot-free (one possibly reformed, the other definitely unrepentant). And the deus ex machina that destroys the major bad guy is not only completely hand-wavy and incomprehensible, but also MIGHT NOT EVEN HAVE DONE THE JOB ARGH.

Seriously there were so many times I just wanted to throw this book across the room, and I just kept waiting and waiting for the payoff as the stakes got higher and higher and then IT NEVER HAPPENED.

Vinge actually makes the ambiguity explicit in the last few pages, when one of the main characters wonders whether it was all worth it, whether they really did save the galaxy, and concludes that, oh well, they'll never know for sure and they just have to make the best of it.

I guess maybe it was supposed to be bittersweet or something, but for me, there was just too much suffering with not enough payoff.