So far so good. Pictures do look pretty near-term however they're not perfect by a long shot.
Admittedly I've been spoilt as I was using a pixel 2 before this, and low light images were a lot sharper, but not as well lot as the s9.
I think there can be a lot of improvement between the 1.5/2.4 aperture settings in regards to software tweaks.
Another thing I'd like to see is a much better portrait mode. Images look so soft and lack finer details. Compared to my pixel 2... well there really isn't a comparison at this point.
One thing I've noticed samsung cameras always do, is brighten up the face of the person in the photo. If you've got brown skin colour it tends to make them look too pale. I've seen reviewers say it can make the person almost look a bit ill! This happened on my note 8 also, and knowing what I know about South East Asian culture, it wouldn't surprise me if this was as intended as South East Asians do like to look paler, using cosmetics, filters or skin bleaching. So is the pale face as intended?
Anyhow, I'd say the camera has huge potential. Samsung just needs to do a lot of tweaking as irrefutable all the right hardware is there.