I'm not talking about minor releases here... Avoiding an upgrade to a major release (iOS 10) triggers an unavoidable antipattern: Every 24 hours iOS asks if you want to upgrade now or remind you later... but that's not the worst part... At times it will show what looks like the lock screen but if you enter your passcode the OS will auto-upgrade the next time you are plugged into power and on WiFi. If you aren't paying attention, you think you are simply unlocking your phone instead of authorizing the upgrade. I have no problem patch releases, but I find that major releases over time eventually bogs down older hardware.