Eh, this thread is a bit disingenous and feels like a bit of a "damage control" because of some users experiencing performance issues post upgrade. Like, we know they're not wrong. Apple doesn't change the performance of the CPU by releasing an update. that's just silly. However, the new updates tend to require more resources than previous and the added load of the new functionalities may make older CPU's feel slower as they're tasked with doing more stuff. More CPU cycles at "Idle" and more RAM as a baseline. But telling users "your CPU isn't slower!" and expecting them to pass off the hiccups and glitches in iOS11 then is silly.