No problems here on my X or Air2..
I have a 6S that I use as a backup phone/iPod and it performs normally too. Maybe you have some type of corruption in your install.. A fresh install without restoring from a backup does wonders, you might want to give that a tryApple won’t slow down them at this time. I am on iPhone6s, it’s time to slow it down.
I think that you have some kind of problem related to something else, maybe indexing or an app doing something in the background. My install on iPhone X and iPad Pro 12.9 resulted in a very very smooth system. There’s no lagging on my system. On the contrary this is by far the smoothest version of iOS 11 I have seen.laggy everywhere
Apple won’t slow down them at this time. I am on iPhone6s, it’s time to slow it down.
Doesn't really seem like that's the case for many. So far it sounds more like some more or less typical things that a few experience here and there at times after updates.laggy everywhere
I don't see that on any of the devices I updated to 11.4.1.laggy everywhere