When I visit web pages based on scrolling, I always try them with a macbook trackpad (or magic mouse) and then with a "click"-scrolling classic mouse.
It's usually great with the smooth scrolling of the trackpad but it loses all its effect with the classic mouse.
Terribly jerky scrolling on my Chrome v 42.0.2311.135
scroll interfaces, like this one, are terrible on tablets. After a swipe, effects have to wait until the page stops then everything plays catch up. More often, it crashes the browser... Like it just did to me on my iPad.
The sidebar floating on screen is buttery smooth