I see what you mean. The animations and behavior of them have reverted back to the iOS 7,8 and 9 days too where they finished opening all the way instead of letting you instantly interrupt them like iOS 10.
It seems every year they tweak something here and there for better or worse with the timing and animations.
I don't really feel like apple wants the 8/8+ to be slower than the 7 was on iOS 10 but that's exactly what's happening by delaying the home button response and slowing these animations.
I don't get it. I think my 7 on iOS 10.3.3 will be faster to bip around on too then the gesture based X. We'll see when I get my hands on one in the store and compare. And we'll see if they ever change the button back but I doubt it will ever happen. This was settled long ago internally.
It's still just so weird to me that they got the animations running nice and smoothly by 10.3 with the instant home button then when they got to iOS 11 some guy was like, "hey this is too fast we gotta take this down a notch and add a little delay for these awesomely fast capacitive home buttons!". And every one was like yeah this feels so much better! Blows my mind.
Maybe they are all just focused on making the X appear faster and better but I doubt they would purposefully cripple the 8 and 7 but it sure feels that way with the current state of iOS 11 and its timing and behavior of animations compared to iOS 10. iOS 11 is just a huge fail with bugs and the feel right now. Imagine if you cut put 10.3.3 on the iPhone 8. It would be awesomely fast.