spin balancing vs bg balancing

I bought new Alcoa aluminum wheels, all 6 tires, and Centramatic balancers. The new tires were simple spin balanced. I ride like a Cadillac at 70 now. I'm not saying, by any means, that you should spend that much money. I have an 03 F-53 chassis, and they were known to have some cheap steel wheels that were out of round in that era, so I fixed it. (The steel wheels are $325 ea., and Alcoa's were $375 ea.)
The Centramatic balancers claim 35-50% tire wear increase. I got'em for the continuous balancing factor.