As an adaption to the latter 2/3rds of the original work, it's a 5/5. They really nailed it.
As a movie though? I would give it a 3/5. The antagonist in the sequel never felt formidable. Dave Bautistas character fails pretty miserably at all of his tasks and his younger brother is given the light to be our villan. The scene in the fighting arena failed to convince me that the harkonans were finally using someone capable. A single duel does not make a war leader.
And I think Paul should have failed at some point throughout the movie. I understand that Dune 1 represents the low point in the novel, but Paul's constant upward movement and the seeming ease him and the fremen won felt cheap.