Frank,
I have a h420, and put an 18" Max-prop on last October, just prior to going south to Key West (mostly inside on the ICW). See archive posts. While I agree w/ Bryce's remarks, I was able to buy the Max-prop at wholesale (thru a 'dealer' friend), so I went with it. I've been very pleased. Performance in fwd. is almost identical to what it was w/ the origional 18" fixed prop (example: 7kts at 2700rpm w/ each prop). Although, in my experience, fuel usage may be .1-.2/gal per hr greater in the 2700rpm range, with the Max-prop. But, the main reason I installed a reversing prop was to have the greatly increased reverse thrust. I had 2 (relatively minor) groundings on the ICW, and the Max-prop pulled me off each time, w/o a problem. That added security, alone, is worth the price. The slight increse in sailing performance (w/ the prop feathered) is just icing on the cake. BTW, Max-props are made in Italy; and the mill/machine work is exceptional. When I first received the prop, it took several minutes (of hard looking) to find the seam between the two sections of the prop housing!!
