I have experience with the dyna beads, and they were OK, but when I had tires changed, they got thrown away, changer didn't believe in them, or ask me about saving them.
So I put some miles on the new tires (Avon Cobra) and they started cupping immediately front and rear with just good balancing. I added the Centramatics, and on used tires (no other changes) I felt a difference right out the door (as soon as over about 25 mph). Smoother at all speeds. The cupping has not gotten worse over another couple thousand miles, so I can believe that these may extend tire life, but like many others, I don't believe doubling. But if it helps prevent the cupping front and rear, it is well worth it.
Oh, and my E3's were getting some cupping with the dyna beads. The next test will be to put new tires on with the Centramatics and see if it cups again.
But I love my Centramatics for now.