The SciFi adaptation of Dune as a mini-series was better. Of course, Dune was too damned long to begin with--there came a point that I just wanted the book to end...Or Dune for that matter.
The problem with Battlefield Earth and Dune was the complexity and length of the Novels. At 185K words Dune is a bit lengthy and I don't think it can be done well as a single serving movie. Battlefield Earth at 428K words can't be done as a single serving movie. Way too much detail loss.