I still haven't seen a video of a device that doesn't lag on iOS 9.
As soon as someone shows me iOS 9 running better than iOS 8, I will shut up and never post about this topic again.
I notice lag in Control Center too. What I am wondering is this: How does a person determine if the frame rate is 60 or 30? Is this something that people are approximating, while viewing their device, or is there a way to actually measure it?