James McAvoy started his career with "Children of Dune" and was brilliant. It has Ian McNiece as the Baron Harkonnen who's brilliant performance dominants the first mini-series. William Hurt does a suitable Duke Leto, and Alec Newman comes into his own during "Children of Dune" as well as the more mature Paul. I disagree that the acting talent isn't there.
I will concede that I've only seen the first mini-series. I've heard Children of Dune is vastly superior in all respects.