I have just finished both books in Peter Watts Firefall series.
I loved them. It was interesting that neither book was "about" the events unfolding and rather seemed to be an examination of consciousness and intelligence (human and otherwise).
I loved Blindsight except for some biochemical blunders, but Echopraxia really blew my socks off, even though I had to read the AMA to understand what the fuck was going on. Really sick book.
Honestly I've read the AMA, re-read multiple parts of the books many times, and researched some of the subject matter on my own time, and I still don't totally get what's going on in Echopraxia. I mean I get the jist but that book is just jam-packed with smart and crazy sci-fi ideas (possibly too many of them). Still one of my favorites.
I really hope PW gets around to a third book. I want more of those aliens.