Speaking of iPhone X, my mother got 1, I used it for about 30mins setting it up with her Apple Watch Series 3, haven't tried the camera though.
I tell you what though, the Note8 and iPhone X are simply not comparable. The iPhone X is a great Galaxy S8 competitor, it's not playing on the same field as a Note8. It's like comparing a Range Rover Sport SVR (Note8) to a Mercedes C63 AMG (iPhone X), both are high end products, but they are two different products.
If you are going for the Note8 ensure you are happy with its size, it is a gargantuan phone, the iPhone X feels puny next to my Note8, the display is too small for me as I am used to the huge one on the Note.