I agree on the "if it ain't broke don't fix it". Someone else made the point once and it makes sense to me. Could you really put a rock between the bars of a spinning cylinderIJ We have found tons of crap in our rock trap and we never ran filler bars except in corn. Chunks of wood are an everyday thing along with metal, turtles, concrete chunks, etc. Our ground is hilly and everything in the world washes down from the roadside. Even at 300rpms those bars are coming around pretty quickly. Kinda like trying to throw a marble through a spinning fan. Too quickly in my opinion to get something inside of them. That's just my thoughts and I certainly think that if what you're doing works for you then you should keep on. I thought I needed the filler bars for corn, but I tried it without them and so now I have no need for them at all, but that's just me.