Neptune's Brood is really good. It's set in the same universe as Saturn's Children but without the Heinlein-tribute sexpot focus. It takes a lot of concepts from "Debt: The First 5000 Years" and extrapolates them to the next 5000 years.

I lovved Neptune’s Brood. I’ve listened to it in audiobook form probably 10x

I havent managed to get my hands on the sequel =(