from what i understand while being around a blown pro mod which we ran for many years with an AFT clutch, the bronze insert will be more forgiving and will be more consistant than the steel. Once seated in after a few passes with the bronze the clutch would hardly wear at all and require very little change in tune up unlike the steel which we would always be throwing more clutch at it after every run as clutch got hot. With AFT, it was a fight to get them to keep the bronze insert on the floaters. They always wanted to put in the steel saying it was better.