Things to ponder...
[1] 4 cylinder power pulses don't match perfectly with 3 bladed props.
[2] 6 cylinder power pulses match better to 3 bladed props.
[3] Ovations were made with 3 and 2 bladed propellors depending on O1, O2 or O3.
[4] My M20C had a yellow arc for RPM: We were to avoid continuous operation in this arc because of vibration harmonics. Honestly, I don't think I could feel the harmonics. I am sure somebody could measure it. But just because I can't feel it doesn't mean that it isn't harmful.
[5] High power and High RPM gave plenty of vibration, but that is outside the yellow arc and prior to redline. Go figure.
[6] Prop balancing is a wonderful thing. After overhaul things vibrated perceptably less. I am sure dynamic balancing is good too.
I think the value goes to the newest propeller, one without rpm restrictions or ADs, no matter if it is two or three blades.
-a-
PS Tom, what was this?
"people interested in Mooneys are typically frugal/efficiency freaks/cheap bastards and this is a buyer's market."
You might look up some threads related to turbos. You will find the concentration of mooney people willing to pay more to go faster.... There is a balance between efficiency "freaks" and speed "freaks" here.
Then there are the folks who want to go reliably in all conditions. They will pay more for air conditioning, glass upgrades and FIKI.
There are people willing to pay extra to put glass into M20Cs, Regardless of wether they will get money back when/if they sell it.
There are mooneys for everyone and every budget. What a country!