Dwight,
I have no data for comparing a metal prop to my adjustable (46" pitch) on my Legend as it was delivered with the adjustable prop. I can say, that on the flight from Texas to home near Buffalo, I was notably faster than the other two Legends, having to fly multiple 360's to stay back with the others. Also, I was able to climb with the one with the Mac 75/35, and at each fuel stop (7), I took less gas than the other two.
At the following thread is a discussion about the effect of various pitch options. If you switched to a 48 or 50" you would gain the speed you hoped for but be back where you were in climb and fuel consumption.
http://www.j3-cub.com/smf/index.php?topic=2325.0Carl