I gotta say this is one of the best ever position sticky, scroll animation fests I have ever browsed. It was smooth the whole time, and handled window resize by basically saying 'fu' to the user I'm going to start from the beginning. However, saying all this, I think it's a pretty terrible form for giving importance to the content. It just continually distracts from the words on the page, and I end up just playing with the scroll toy instead of caring about what the article is about. Maybe sour grapes, because I struggled with similar web projects in the past. So I have true admiration for the makers of this but I feel like it turns the page from some article about the macintosh to a cool scroll experience.