Heretics of Dune is a bad and horrible science fiction book. It's definitely one of the worst books I've ever read. I didn't think it was possible to write something as bad as God Emperor of Dune, but obviously (and unfortunately) it was possible.
I can give Heretics of Dune only one star, because it doesn't deserve more stars. In my opinion this series should've ended after Children of Dune, because the other books are unnecessary sequels.