Everything is a compromise. A three blade prop will provide more drag under sail than a two blade prop. They do reduce prop walk and better low speed capabilities. Before making a decision check the percentage of time you spend motoring vs. under sail. If you motor less than 20% of the time I would not bother.
I had a 3 blade Michigan Wheel.
I replaced it with the shaped Campbell Sailor by “North by West” in Comox BC.
KELSEY helped identify the best size and pitch for my boat based on the boat, the motor, and the transmission.
Results 1.5 knots faster under power. I reach hull speed at 95% of WOT.
.8-1 knot better sailing speed.
No prop vibrations when surfing on a swell.
Less prop walk.
I am very pleased wiling the new prop.
13X10 (13" Diameter 10" pitch) 3-blade give the best motoring performance for an M25XP. Feathering props give the best combination of power and sailing speed, but they cost a lot more than fixed blade props.
@Kingjim91 Those props are good props. They are known as "Michigan Wheels" and make up a major proportion of the 3 bladed fixed props on sail boats or power boats. Two reasons. Large production and reasonable costs.
The big ears (blades) on these props contribute to two of the often voiced problems with boat handling. Prop Wash (or Walk) and reduced sailing speed due to prop drag.
In order to address these perceived weaknesses, boat owners have chosen alternatives. Popular are the folding or rotating props that greatly reduce prop drag by causing the prop to feather into the water stream. It works in the same way as a prop plane feathers the prop to point the blades into the wind reducing the drag.
Another alternate is based on reshaping the prop blade. The CampbellSailor takes this approach.
Which ever path the SBO takes it is a compromise. The fast way to sail is to have no prop in the water.