More on iOS 9 and older devices
Apple favoured support and compatibility over user experience, and decided to extend the life of the iPhone 4S and similar devices anyway, when a more reasonable approach would have been to stop support at iOS 8.4.
Author: Riccardo Mori
iOS 9 on the iPad 2
Barely usable, unfortunately.
The first Spotlight interface is still the best
Spotlight in OS X Yosemite and El Capitan is getting better, but I still prefer the original interface it had when it debuted ten years ago in Mac OS X Tiger.
Patronage model? Good luck with that
I think that the patronage model doesn't scale well and may ultimately be unsustainable.
f.lux must be allowed on iOS
f.lux has a really beneficial impact on your health: it leads to much less eye strain and a better sleep. It deserves a place on iOS.