I did a bunch of "research" (asking as many 235 owners as I could
find) about this two years ago when one of my blades failed
inspection. Almost all of them reported some sort of vibration.

I've heard this before, but I don't understand why an extra blade would
inherently add vibration?

If anything, shouldn't an extra blade reduce vibration?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"