I just got my eighth pair of ON shoes. The ONs that I have tried are the most comfortable walking around and gym shoes ever. They are also the best looking shoes. But, for running, they are all garbage.
I've had the Cloud, Cloudnova, Cloudswift, Cloudventure, and one I don't know the name of. None of them feel good for running at all, and the soles pick up rocks, twigs and pine cones like crazy. They are also deadly slick on ice, snow and wet pavement.