Those with lag, stutter issues you may try this as it reduces processor load and you give up nothing much in my opinion. Purists and android trolls please refrain from commenting about, not having to turn $h*t off.
Go to settings > general > accessibility > reduce motion > turn this on.
Also settings > general > accessibility > increase contrast > reduce transparency > turn this on.
The novelty of these wore off for me 1st week. I rather have next screen pop up and I have found an increase in speed and don't notice any stutter. Not much to loose giving it a try. I'm sure the A9 chip will eliminate any stutter, but I still intend on keeping these settings turned on, as I have become to like the minimalistic look. And why waste processor on something I don't want.