I saw this in Dolby Cinema last night. The image was very naturalistic. Nothing showy for HDR, save for some scenes at a beachside carnival at night. Same goes for the Atmos. Nothing bombastic, but there's some effective directionality when necessary.
As for the content, it's just as creepy as you'd expect. The tension is very effective. (When talking about horror, I always have to give the caveat that no movie has scared me since I was a kid, so I can't judge how scary it will be for you.) Like Get Out, it's an original story that works on multiple levels with many ways to interpret it. How deep you go is up to you. But I enjoyed this immensely. And I think this will benefit from multiple views.