My Choice? Your Choice
I chose to put an Autoprop on my new C-36 last year. I didn't even try the standard prop. I suspect that most Autoprop or Maxprop users will tell theirs is best. Who will admit that they made a $2000 bad choice? Almost no one will have had both brands on the same boat to compare. My take on it: Autoprop - probably more efficient under power and especially motor-sailing since the prop always finds it's own best pitch. Sort of like an automatic transmission. Good speed gain under sail with the feathering. A few users report a little more vibration under power. (I don't notice it.) Some people also report they have to maneuver at speeds above slow idle to get the blades to start to grab. Some people choose to add a little length to the prop shaft with a "drivesaver" to give more clearence from the strut depending on your boat. I can twist the blades around to touch the strut on my boat when out of the water but can't make it touch when under power. Maxprop- slightly less drag under sail because the blades are flat rather than cupped like the Autoprop. Good motoring power compared to standard prop, but not quite as good as Autoprop except perhaps at full power. Since the pitch can only be adjusted for max efficiency at full power, the efficiency at part throttle or motor sailing will be less. Because you have to adjust the pitch yourself, some owners report having a diver make several dives and adjustments before they are happy with the pitch. This seems to be trying the reccomended setting and then trial and error to get it perfect. Probably not that great a deal unless you are a perfectionist and it is only done once. Racers may prefer the Maxprop and cruisers the Autoprop. Both blades will give a great advantage when sailing and have little prop walk when in reverse. Buying it along with the new boat like I did is easiest and will maximize your investment, but if you wait a year to install you can report back to us the improvement. ;-)
