I had to sell my wife's iPhone 4 after I upgraded it to iOS 7. It made it unusable.
Unlike android or windows phone, I could not roll back.
It's ridiculous, my iPhone 4S almost five years old on iOS 6 can perform just as well as my new iPhone 6S.
So what can be concluded here? Well iOS has become a lifeless,
I know, that's what I'm afraid of. Apple has been good to me and I don't want to see the company crash and burn (even though they have plenty of money lol).+1
This is one of the problems with "devices". The device (PC, Smartphone, tablet...) has an OS and the manufacture (Apple, MS, etc) wants the OS the be the focus or at least part of the focus.
That's where things break down, many people don't get a dam about the OS. They care about the software (apps). To the user, they hold something (iPhone, Lenovo, Samsung,...) it has an OS and then the apps.
The main thing the user cares about are the apps. As long as the device and the OS do their job well (fast, functional, etc...) they don't care.
I was pissed when so many apps no longer supported < iOS7.
Apple has such pride in their upgrade rate, yet they seem to forget that they are reaching the point of "is it really worth upgrading for" as their sales for the first time in 13 years, didn't grow.
If they continue down this path, they'll continue to slow.