That's one big problem of iOS isnt it? System-wide scrolling lag. Whether you want to admit or not scrolling on iOS is pretty lethargic and slow compared to Android.
And all you show is ONE app which lags in Note3 and you label the the whole phone lags. I can make a video of how Safari lags in loading up few tabs or some ill-programmed app lags and then label 5S as a lag fest. But I won't do that because that is naive. As you can see from your video, it is not Note3 that lags. It is the app that has issue. I believe the app was My Magazine which is a derivation of Flipboard. Flipboard app doesnt have that kind of lag.
iOS has SYSTEM-WIDE scrolling lag and you call that "slow scrolling" a feature. :p
Lag is when your phone is taking a long time to do what it should.
not when it does what it should at normal speed.
How much fun is it arguing if you make up the language, the rules and the facts??