Posting on MR on how the milliseconds turns into seconds, negates any slowness at all if you are looking at the totality of your life as to where your time is spent.Those milliseconds add up to seconds over multiple releases. And thats in addition to those small stuttery animations which are not there on iOS 10. iOS 11 stutters at least twice or thrice in animations on a daily basis. iOS 10 has zero stutters. Its also designed with home button devices in mind. Hence why even the iPad home button is faster on iOS 10 than 11
Having said that, I am more concerned about a fully patched phone, than any millisecond difference between any two IOS releases. I don't have any animation stutters on my phone running ios 11.4b6 in any screen I am on, which admittedly is not every screen in every nook and cranny of IOS(I only care about what I use, not what I don't use). Each persons experience is different and has been reported differently through the ages here on MacRumors.