I think the OP may have been more concerned about damage to his prop-shaft/lower unit. Is there any truth that prop-shaft/lower unit damage is less likely in case of a strike if an aluminum prop is used?
I always heard that an aluminum prop will save the lower unit, because the blades will sheer off. Last April, on Palestine, I hit a stump with my 90hp and took off 2 of my 3. I put on my backup prop and was good to go.
I was just thinking about going aluminum for the weekend, then back to stainless on less stumpy lakes.