I recently swapped out my Hartzell prop for the MT composite 4 blade and have had a chance to fly it a bit and thought I would post a report on what I have observed. Special thanks to Erik B. and Scott S. who provided me counseling on their experiences.  By the way, my Hartzell is listed for sale with a complete overhaul. Buying Process - I ordered mine from Flight Resources.  The delivery took 4 weeks, 1/2 down up front and 1/2 when it ships from Germany.  You must have the prop shipped to