I first saw Koyaanisqatsi at the local arthouse theater a few years ago, and to me the most powerful things were the theme music and the time lapse shots of the space capsule falling to the ground.
I think they're a good example of the "hyper" approach to realism: by using acceleration, decelerations, rewinding and forwarding the image, by mixing static with movement, they show another reality, another way of conceptualizing the world. I find it actually has scientific overtones: Marey, Muybridges, and countless other scientists who use these cinematographic/photographic techniques to study nature.
It's as if they can render visually the thought process of abstraction. When you see a flower bloom a few minutes after having seeing it closed, you have to make the mental jump to connect the two. With time-lapse, you are actually seeing it, and you experience this continuity rather than positing it.