OK, ignore any of my recent comments you may have read about me sticking with my iPad Air 2.
Since playing with the Pro 10.5 two or three times in the store, I'd come away happy with my Air 2. I wasn't blown away by the screen but I did notice I missed it a little when I used my Air 2.
Today, with a caffeine hit and a single sentence of encouragement from a friend, I upgraded to the Pro 10.5.
Now, after reading a book I'd been - up til now - reading on my Air 2, I suddenly 'get' ProMotion. Scrolling slowly as I'm reading, with ProMotion, TrueTone, low reflectivity, and the slim black bezels (all new to me), this thing feels like a moving magazine or newspaper. Scrolling quicker ruins the illusion, but slow scrolling... This is amazing.