Throwing this one out there... feel free to dispute it if you like.
One thing I have noticed about the V10 camera is the lens window can scratch easily. I have managed to put "very" faint scratches on mine from gently wiping off the dust and debris. I think its the AR coating on the lens. You can buy replacements, but AFIAK many of the 3rd party parts are not AR coated... and they are hit / miss in that regard.
I am not sure how this compares to the V20, but with a camera glass window that large / protruding, I think its something V20 owners should be careful with.