I have a balancer as well, and although I balance all my props, I wouldn't stop flying because one isn't balanced. Some props are better balanced than others. MAS seems like always needing tweeking. But in all reality on small engines, unless the prop is really bad, it's not needed. On the bigger props I think an unbalanced prop could add undo vibration to the firewall, fuel tank and airframe. All boat, and airplanes props are balanced.