I use the puff balls as well. I have tried most of the rubber ones and just don't like them. They all make a rubber whizzing sound of some sort that bugs me. And some of them don't last that long. The yarn puff balls are really quiet and last for darn near ever.

The only down side is when walking thru woods they pick up every little thing. And the get wet when it rains. I haven't noticed where it makes my bow shoot any different though. They are pretty cheap as well.

Paul