Hi Mike
Thanks for your comments. In essence, I don't disagree with you. Like everything else on a pleasure boat, the choice of prop its a matter of compromise between competing and often mutually exclusive performance characteristics. Not forgetting the cost. However, if we are comparing apples, we must make sure we compare exactly that. It is in that context that I found the article useful.
In my case, the choice of design is limited by the available space. I can't fit a folding prop, so I am left with fixed blade and feathering design types. Hopefully -one never knows- I will not regularly have to steam for long periods at cruising RPMs, so speed and fuel performance within that range for my engine (a Beta 16 hp and a TCM 40 gearbox with almost identical fwd/rev gear ratio) is a lower priority. On the east coast of the UK, I use the engine to maneuver in and out of moorings and fight the tide in channels into harbour. Therefore I need a prop that will give me good bite in reverse and at high revs forward. This would suggests a traditional three-blade fixed prop. However, as you point out, a 3 blade fixed will probably represent unacceptable loss of performance under sail and pointing ability. Probably... have not done any testing myself! All the above considered, plus the price differential between a Kiwiprop and the other feathering props, makes the Kiwi an attractive choice.
Have to decide soon and can't do the testing myself, so gathering the experience of other skippers to help me choose is one of the reasons I started this thread!
Thanks again.
Rafa