No, I had oversized slightly domed, brass resonators put on one of my VI tenors at last overhaul. You'll notice no difference in key response or weight in the horn. You may notice minimally enhanced harmonics in all ranges and slightly more projection. I am personally pleased with the minor enhancements but I would suggest you wait till you need an overhaul as the positive differences are slight. I have nothing negative to report.heath said:Do some of these over sized reso's cause the key work to be sluggish. I know the plastic reso's that selmer sends the horn with are pretty light.