I have followed Paul Lipps prop design efforts. Very interesting indeed. There must be some improvement in efficiency since the birds flying them are usually near or at the front of the pack. Looking for improvement is admarible Ed, The problem is often you must just build it yourself. Paul's efforts, at first at least, were the design program only. He would give you the numbers for the speed and HP you had and then you had to fabricate the prop yourself! I don't know if he is supplying a finished product yet or not.
Look under heading BiPlanes in the below URL and there a pilot reports a 20 mph increase using the radical Lipps propeller over a more conventional prop - again, my point is better ways may be more a matter of looking at fresh ideas about props and controllers rather than accepting what has been.
I believe this prop is optimized for high speed flight, and while I am certain I don't fully understand the total reason why, part of the reason it is faster appears to be that it can develop thrust right down the hub if the airspeed (prop advance?) is high enough. Also the developer takes issue with the standard "broad" tips on props. etc.
However, it may not provide the same amount of increase over my current prop due to the slower airspeeds I flight - but hey, even 10 MPH increase would be interesting.
FWIW