Back in the day when P&S cameras were going through megapixel wars, it was a well-accepted that the sensor size affected image quality a whole lot more than megapixels. The average point & shoot sensor size back then was 1/2.5". Based on what I can find, it looks like the sensor size for the iPhone 6s is much smaller at 1/3". So, does the 12 megapixels really make any difference in normal use, or does it just waste storage space on the phone (and also wherever else the photos are stored)? Is there a way to set the camera to use a lower number of megapixels?