Well, I tried force3d and it for sure makes my animation a little bit more performant.
But the original problem still exists. Just to be clear: the scrolling-movement itself runs just fine, but during snapping it acts like the animation gets killed after each pixel and starts again. Exactly like I've seen it before with the iOS-autokill-bug.
Sidenote:
And the original demo doesn't have snapping enabled, that's why I made a fork.