Yeah I did notice, all I was saying is that it's not quite so relevant to compare to the 6/6s/se/whatever due to the difference in the architecture. 7 to 7 comparisons are obviously fine as they share the same architecture and can be reliably compared.
I was just mentioning the 6+ to show that even older devices are running ios 10 smoothly now - there is no way the 7s should be lagging, even going to the less intense processors. Unless he has a 7 plus then there could be an issue with the higher 1080p resolution, there was an issue with poorer performance on the 6+ for a while.