This is a sequel of sorts to REAMDE and ties both books into the shared world of Cryptonomicon and The Baroque Cycle. I thought it handled this pretty well, particularly in the handling of a mysterious recurring character, but I’m aware opinions on this may be divided.
The books spans a long period of time across two very different environments and handles some fairly complex philosophical and technological questions as it portrays the fates of the various protagonists and antagonists.
Character development is an interesting question given the book’s premise. To say too much would potentially introduce spoilers so I’ll just say that some aspects might focus more around the core essence of a person’s identity and behaviours across distinct sets of only loosely-coupled lived experiences.
Some sections are more overtly fantastical and science-fictional than others, and some sections introduce interesting social and cultural issues and characters only for them to be left behind without further reference as the book progresses, which is a slight shame - what happens to all those Leviticans and other Ameristanis? Surely they don’t just stop having kids and line up for an essentially secular afterlife (despite all appearances and amusing references to poly- and monotheism)? It’s also a shame that the desirability of a posthuman singularity built and dominated by the 0.0001% isn’t really tackled at all, which is closely related to the last point.
If you’re a fan of the author and enjoyed REAMDE in particular, although this is quite different, it will probably appeal. Despite some misgivings, I enjoyed it.