I liked Brin's
Kiln People, and
Glory Season, but I found
Earth too aggressively propa-green-dist for my tastes -- it's not that I mind a story that assumes Global Warming as a setting/plot point, but it seemed he had to keep telling me about it (in a somewhat preachy manner) every third page, I gave up about 1/3 of the way through. Too bad, really, I found the story concept quite intriguing.
One thing about Brin, that I like and dislike at the same time, is that he almost never
explains anything, you have to figure out what's being discussed from context. That means you don't get the story line interrupted by a lengthy treatise on, say the political/culture structure of a colony world that's been cut off from the rest of the human diaspora, but you have to spend a lot of time/effort figuring out that structure from the contextual off-hand comments and interactions of the characters. It makes the story flow nicely, and it's a good intellectual exercise, but it can be confusing in the early part of a story.