Saw it yesterday, thought it was mostly very good but wasn't super blown away by it as a whole.
I though visually it was excellent. The acting and the way it's presented is all top but like others have said it felt a bit rushed which is tough for a nearly 3 hour film.
I mainly wasn't sure about plot changes from the books (spoilers ahead) as they've obviously massively sped up his time with the fremen. Paul has an infant son (who is killed when the sietch is raided, giving it all more emotional weight) and Alia is born and is like 4 or 5 in the books? So he's there for years. He also falls into a coma after drinking the water of life, whereas here he's just... unconscious for half a scene? It loses its impact.
It essentially becomes a film about some OP guy who barely gets a scratch laid on him for entire franchise (until the final fight needs a bit of drama). I know it is quite like that in the books but it took a lot more time.
Also as people have already said, rubbish villains really. I know it's kind of the point in the books that the fremen numbers are so high that if they believed and rallied they'd outnumber them easily but the battle (whilst looking incredible) was over so quickly it felt like we were deprived of more of that spectacle.
Rabban was also pointless, just screaming in every scene before dying in the world's shortest fight. I mean if you're gonna go down the cliche action route of "Well look who's back from the dead" vs "I'm avenging everyone you killed", at least make it a fun fight to watch? They build up this history between them and then it ends in two swings of a weapon. Same with the baron. I can't even remember how he died in the books and I know killing him wouldn't be hard but they had Paul basically come in and euthanise him.
Also I know he's very much a believer in the books too but they turned Stilgar into a meme basically. People in the cinema were laughing at most of his scenes which felt a bit out of place for an otherwise serious movie that didn't really use dark humour.
I didn't intend to write all that
but yeah, enjoyed it still. Sandworm bits looked incredible.
EDIT: Also found it weird they left out Feyd trying to cheat in the final fight. I thought they were planting seeds for that with the drugged prisoner thing because he clearly didn't want to fight them 'fairly' but it just didn't happen.