Initially, I also thought the spiders were a bit too "human"... however, in thinking about the way Vinge portrays them, it was important for me to realize there's a point later in the story where he reveals that the focused translators are heavily anthropomorphizing everything they relate to the rest of the crew. I think this is a really strong suggestion that everything told from the point-of-view of the spiders is passing through the same narrator. There's a point where he specifically mentions that the translators seem to know about events and conversations they shouldn't, and we can infer this is because they've been covertly communicating with the Underhill for a long time and he's given them the back-story.

Also important, I think, is that a huge contributing factor to events and technologies developing similarly to those of human civilization, is that the humans were actively manipulating information and events on the planet from the moment they arrived.

I agree with you about Stephenson being fantastic; his books make you think. While I've enjoyed what I've read from Vinge, in some sense it feels much closer to the fantasy genre.

I'm curious as to what folks here thought of The Baroque Cycle. I loved Snow Crash, Diamond Age, and Anathem... but Quicksilver seemed to drag, and I didn't have the heart to pick up the next one in the series.