Just finished this. There are elements of the book I like - some of the overarching story is intriguing and you want to know what happens to these characters. The book accelerates towards the end in this manner, the last 100 pages were very hard to put down. Unfortunately there are substantial chunks of the book that I felt were pointless, the author showing off, or just labored. There is far too much time dedicated to robots discussing the intricacies of Shakespear and Proust - I'm not reading this ancient literature for a very good reason, and I dont expect to find it here. It comes across as Simmons showing off at your spare time's expense. You can happily skip all this junk when it happens and lose nothing of the story. The other stuff concerns the Iliad theme in the book; there are many pages dedicated to describing Greek heroes, their superfluous dialogues, and endless battles. I found this tiring, it could have been cut in half with no impact on the story.
So just 3 stars. The book is a bit slow to start, and contains far too much irrelevant junk. But if you can get over that, the overarching story is intriguing (though I wouldn't say compelling).