I didn't love A Fire Upon the Deep because, while the sci-fi parts were amazing, the medieval fantasy telepathic dog society was much less interesting, basically a political fable with some children thrown in; it seemed like a different novel altogether, and in fact the plots don't really ever intersect except when the adults finally land. It felt like two very different books cobbled together from two different authors. The dog half reminded me of Terry Pratchett for some reason, another author whose schtick involves making the story go faster and increasingly more breathless towards the end, like some Hollywood action movie, often involving a bunch of running or flying.
I liked Deepness even less, because once again you have fantasy politics, and while I understood the conceit, the storytelling just didn't work for me. Like before, the science-fiction stuff was fantastic and full of great ideas, but the other half was the exact opposite.