I've got a 32GB iMac here, and in Chrome, on full screen on my 27" display, the animation worked smooth as butter. In fact, the smooth scrolling added to the whimsical, arty style of the site for me, leading to a great experience.
EDIT: Actually, I just tried it again in entirety, and noticed some juddering from time to time. However, when I am looking at the beautiful background artwork (which is most of the time), that juddering is less obvious. I guess it depends if you are looking at the background art or the foreground animation as to whether it is really apparent for you.
EDIT: Actually, I just tried it again in entirety, and noticed some juddering from time to time. However, when I am looking at the beautiful background artwork (which is most of the time), that juddering is less obvious. I guess it depends if you are looking at the background art or the foreground animation as to whether it is really apparent for you.