It's really good. The series is about the sentience "Bob" which is uploaded into a self-replicating spacecraft and then travels the galaxys, helps the humans, ... etc. I won't go into spoilers here. The topic of "artifical" versus "natural" intelligence plays a major role in the books and "Bob" is confronted with many situations in which he feels very human and/or very computer and/or struggles with the line between the two.

The pacing is very well done. The book overall is well-crafted and VERY WELL RESEARCHED. Yes it's still fiction but I'd say 98%+ of the book is based on real & possible physics.