In my opinion the latest installment of the Dune saga, "Sisterhood of Dune", is one of the best works of the Extended Universe and possibly even of the entire saga including the Orthodox Herbertian Universe.
The story is set several decades after the Butlerian Jihad is over and after the evil thinking machine Omnius was defeated.
Sisterhood is action packed - as any Extended Universe book - but does not lack of the political intrigues and complex personalities of Frank Herbert's original works.
One of the focal points of this book is the obsessive and hateful behavior that might move entire civilizations and peoples toward hate for a now defeated enemy. In Sisterhood the Butlerians -which are the true moral winners of the Jihad - are so religiously obsessed by the idea of the thinking machines that they don't feel any regret in committing murderous and damaging activities in order to fight for their idea. In a beautifully described plot, the Butlerians guided by Manford Torondo which are supposed to defend humanity from thinking machines reach the paradoxical point in which, in their mind, the thinking machines have become more important than humanity itself.
Sisterhood contains many subplots including the unexpected return of a never-aging Vorian Atreides, other known personalities and locations (yes, Arrakis is in this book).
I truly enjoyed reading this book, although a word of caution is necessary. If you haven't read the preceding books in the series then Sisterhood of Dune might be a difficult read. The authors try to summarize what happened before (for those who have read the preceding books it could seem that sometimes they try too much) but it might be not enough to enjoy this book.
Right now I can't wait for the next book in the trilogy, "Mentats of Dune".
Have a good read.