Hi SteveO,
I’ve had both, up to 250 hp motors. For one thing, a good ($400 + ) stainless prop will keep you awake much like haveing a new 9.9 trolling motor hanging on your boat!
An ugly aluminum one hardly ever disappearsd, if you know what I mean.
The other thing is, alum. props are cheap by comparrison, and there are a lot of them hanging on the marina wall that never got picked up after the repair was done.
It’s cheap insurance to have a spare one of those on board.
One more thing — an alum. prop seldom ends a fishin trip if you happen to hit bottom in a shallow rocky area. Just replace it with your spare. But a stainless prop can take the shaft with it, or at least bend it enough to end the weekend.
For my money, an alum. prop is the way to go, but if you must, see if you can get a loaner on the CRES unit before you committ the $$, because they do things to the CRES units that can’t be done to the alum. ones. And that can make a prop of the same pitch run much differently at wot.
Regardless of the prop type, it should let you run within 500 rpm of top speed rating of your rig. If not, it’s too steep a pitch. Back off one pitch and try that one.
On the other hand, maybe top speed isn’t your thing so get a prop that gives you a better slow speed performance. In that case, it’s hardly worth the extra expense of the CRES unit (which really do better at higher speeds).