Swim an old one and swim a new one. The old ones for some reason just seem to swim better. I also prefer the way an older one sits in the water. I think the plastic in the old style maybe less dense, but not sure. Like so many other things (ie whiplash

) I wonder why they ever changed. I am gessing the source of plastic changed, which can make all the difference in the world. I am lucky that I still got a fair amount hanging around.