Well, the operator will have a big influence on longevity. I don't know how to explain the prop thing.

I remember some customers going thru drives like popcorn in the '90's. 4 blades just seem to break more often. A Blower motor making 600 some odd hps breaks more than a 600 hp non blower. The bigger the boat the more they break. If it can go 90 mph your on borrowed time. IMO

It is possible to get them to live. But you can't beat on them.