I think the quality of the screen is important to most when buying a phone which includes color reproduction along with brightness, etc.
No one wants to shell out $1000 for a flagship and have a red tint on images like on the S8s right? No one wants a poor looking display where colors that are not true to the original right? At the very least we want images to be as close to true as possible. As much as many like some punchiness or over saturation in colors and images, many don't want it at ridiculous levels.
I like it that the Note gives you options on choosing the color profile you like and do go with Samsung's Active Display setting myself for a little punchiness.
From Displaymate, (The X display) "is the most color accurate display that we have ever measured. It is Visually Indistinguishable from Perfect, and is very likely considerably better than on any mobile display, monitor, TV or UHD TV that you have. So photos, videos, and online content and merchandise will appear correct and beautiful." That's why you want a color accurate display.
Apples thing is going for accuracy and probably worked with Samsung and maybe even display mate to do it. Samsung could easily do this if they wanted.
The Note was the best a couple of months ago... now it's the X. They are just tuning these things better and better and it benefits all of us in future models. It is just one site though like DXOMARK is for testing camera quality so take it for what it is.
Really? Does anyone buy a phone for color reproduction? Is that all you have to go on comparing the 2 devices?