There were several things in addition to the adjustments they made to the clock frequency curve others have mentioned. There were a couple of fixes in Autolayo

There were several things in addition to the adjustments they made to the clock frequency curve others have mentioned. There were a couple of fixes in Autolayout constraint resolution that were at least quadratic but are now linear. The prefetching in table views was optimized to make scrolling them smoother. A lot of RAM is saved by big improvements to the backing stores for image resources. They made app launching faster. The on screen keyboard comes up faster, and they made it respond to typing faster. Opening the camera from the lock screen has been made faster.