I couldn't agree more. The story feels rushed. The hero succeed in every attempt. There is a small internal struggle for him but it's basically it. Therefore the enemy seems weak. You don't feel any adversity for the hero.
"Paul was swell, I was cheering for him all the way!"
-- Elric of Melniboné, probably
Don't get me wrong, Dune is my absolute favourite book, I must have read the whole series ten times already, but heroes in that world are in short supply. The guy that comes closest for my money is Duncan Idaho, especially later in the series (God Emperor and beyond).