Got mine yesterday (XL), some initial thoughts.
Feels much bigger than my S8 despite being not that much bigger when you put the 2 together. The screen seems way bigger, and better. I think some of that is due to display not being curved.
Been playing on and off with Nacho Noch. Works well, but somehow makes the display seem smaller - even though there's no content going into the 'ears' at the top, it does make it feel like the display is larger.
Not a massive fan of the new navbar/gestures. The gestures are ok, but seems a waste to have the navbar always visible and again goes to make the display seem smaller - I might have to play around with some of the other gesture navigation options.