I agree - don't mess with the catalytic converters. That being said I recently replaced my mid pipes with Borla's to get rid of the resonators and increase the loudness of my exhaust a little.......and it did VERY little. I was mainly concerned looking at the stock pipes about the kinked areas and I wanted to remove any possible restriction. The stock resonators are a straight through design and are NOT a restriction. THey are perforated to an outer shell which has a flat area, but I cut open my mid pipes just to confirm they were not restricting flow. But I don't see their removal making a big difference in sound level or quality. If you want that, change your axle back mufflers instead. You can go mild to wild depending on preference regardless of the resonator pipes. As for drone, I can say for sure that I have no drone with my Corsa axle backs, either before and after the resonator removal. And you can't really trust the you tube sound bytes as I have found none of the exhausts really sound good on video. Go to a Mustang meet and hear them in person if you want to know how they really sound.