Earlier quoted context omitted.
Here's an iPhone 5 advertisement about that exact feature. https://www.youtube.com/watch?v=Af0gtsjfy7E
I think I'm the only person who likes iOS's reachability gesture. The only annoying thing about it is sometimes it will trigger touchUpInside for buttons along the bottom of the screen, navigating me away from the screen I was on.
I am on the 11 (I think? I've lost track, but its the one with three cameras), and the screen is slightly too large for easy one-handed use, at least in my case. I might opt for the mini if/when I decided to get a new phone, but throwing $1000 at a new toy just because it's slightly more comfortable in my hand feels like a very "first-world" solution to a not-really-problem. None of the other features this phone comes with feel like they bring any extra value to my life or warrant an upgrade.
But hey, newer, faster chips mean it can probably run Doom now, right?