There are some ridiculous changes to the story, and the end is so weird that it's funny, but the dialogues are so much better, the characters have substance. The scary ones are scary, the glorious ones are glorious. There is actual development in Leto. The whole world feels deep. Altogether, it feels like it was aimed at a more mature audience. The same audience that would also buy the books afterward if they didn't already read it.
New Dune however feels more like Young Adult Entertainment. It looks fantastic, but the rest doesn't really matter. I didn't feel anything for any of those characters. Some of the dialogues were really cringe worthy (the Hangar dialogue for example) I went there with someone who never read the books. They were confused also didn't bother with most of the characters or what has become of them.
I will go and see the second one though since it's Dune and I love Dune and this might also be the reason why this way of making movies works...the nerds still go in even if they complain and the "normal audience" gets something which won't be too challenging.