I'll rate this book as one of the best sci-fi books I've ever read, right up there with Dune and Foundation. The fact that it was written in 1966, years before the age of the computer, is just remarkable. Heinlein manages to accurately predict so many things that we take for granted today: Big Data analysis, predictive modelling, voice recognition, social media marketing, pervasive electronic communications ("internet"). And this is just the computer side of things, scratching the surface of what this book is about.

The book may be categorised as sci-fi, but it's really about the human condition. The political drama is superb.

Highly recommended.