Mr. Liu's second book in the Remembrance of Earth's Past series, "The Dark Forest" is better than first book.
The sociological concepts played out in "The Dark Forest" are fascinating and complex. More so than the 'Science'. Though the ending is abrupt, once you realize there was no other choice, given the sociology presented, it makes sense.
Forgive me if I am committing heresy, but these two novels very much remind me of Asimov and Clarke.