House Harkonnen is compulsive reading. I certainly enjoyed meeting pardot Kynes and Liet, learning more about the Freman, as well as Gurney Halleck, Duncan Idaho and the Lady Jessica. Such vile villains...and such a fascinating description of splendid places.
Those who long to return to the world of desert, spice and sandworms will be amply satisfied
House Atreides is a terrific prequel, but it's also a first-rate adventure on its own. Frank Herbert would surely be delighted and proud of this continuation of his vision.