I approached this novel with trepedation. A Fire Upon the Deep is one of my favourite books ever, a combination computer-science inspired ideas and super-epic space opera. This is a sequel to that, it had a lot to live up to, and, well, the reviews weren't great.
My fear was that it would be underwhelming. Set on a single planet, with very little technology, it could veer towards a fantasy-style setting with a few hundred humans living amongst Medieval Wolves (TM). A friend had exactly this problem with the novel. I didn't, really. Despite the limited scope, it has Vinge Space Opera Melodrama! There is Betrayal, True Evil, Epic Chases, the works. I was soon deep into it, and really enjoying it, Big Space Battles or no.
(Pretty much literally,) In the end, I felt let down. At the end, Good should triumph, and Evil fail. The ending was far more ambiguous. It's not so much that I can't cope with a little bit of uncertainty, but for a structure like this you expect some resolution, and the ending is not so much unexpected (which could be good) as horribly clunky. It felt very much like the middle of a trilogy. However, with no hints as to whether there's follow-up, and after bashing through 650 pages, it's a good old let-down.
From there, my suspension of disbelief shattered. It felt like characters would do dumb, non-sensical things, purely for the sake of the plot. People would be oblivious to the machinations of the cartoon villain. With the right pacing, action and plot, this wouldn't matter, but the plot didn't satisfy. For me, the loose ends of the ending led to the rest unravelling.
PS: A little search reveals people generally expect a further sequel. Fingers crossed there'll be something to give me the closure I so desire!