Anyone can see your comment history here.
And the video was clearly ffwd, just look at how fast his thumb moves... What's that? iOS 8.4.1 gives you super human capabilities too?
Don't take me for a fool!
I took the video from my iPad 4. I don't even know where or what to do or use to speed up my video even if I wanted to go through that trouble. I'm on 8.4.1. There is no public jailbreak for it available yet. I don't have bionic fingers. Maybe I'll post another video later again with my iPad. It's just such a PITA because I have to hold it and use my phone at the same time that's why the video was a little shaky.
Chill out man 8.4.1 is more responsive than iOS 9. It's just a fact. Even a 6S wouldn't be able to react as fast because of iOS 9 holding it back by making you wait for animations to be over.
It seems pretty clear to me that you haven't used iOS 8 on your iPhone 6 very much. You'd remember the feel and speed otherwise.