Just a quick take as my girlfriend received her note 7 replacement V20 last night.
The camera shoots faster and cleaner in lower light than the V10. The front camera is much better than the V10 as well. Took shots side by side with my V10 and the V20 is easily the better option in less than ideal lighting.
The 2nd screen is definitely a bit brighter
The feel of the finger scanner / power button is very solid.
The phone feels great without a case. Seems very well built, time will tell. While I wish they would have built upon the V10 style, this V20 fits much better with current mainstream smartphone designs. It should definitely get some interest, especially from Note 7 users.
Can't wait to get mine. I was waiting to see it before deciding on this or the Pixel XL. No doubt I'd love either. I still like removable batteries (bet Samsung wishes the note 7 had this now) and the IR blaster is something I use.