Sisterhood of Dune is a novel of multi-level complexity and yet is simplistic enough in it's vision of an as yet untold history within the Dune universe.
I really liked the focus on the story, following a number of decades after the Butlerian Jihad, where humanity rose up and threw off the long years of Machine rule.
But as one power vacuum is removed, another takes its place in the form of the Butlerian movement and their unending quest to destroy technology at any cost (the paradox being that they don't mind using technology when it suits them, thereby travelling in starships, going from world to world to continue their crusade).
I also liked the varying viewpoints from different characters and ideologies, and also the true birth of the Sisterhood and the planting of the first seeds that leads to its own desire to control humanity through genetic selection (a goal similar in many aspects to the Butlerian cause).
With various factions now turning against the Butlerian movement, the following two books look to be leading to something quite spectacular, and the return of a powerful force, but this time controlled by humans.
Well worth reading if you like the Dune universe.