Hummm
Heavy
Cost, no OEM deal. For some reason, could be wrong McCauley never really has courted the experimental market. Hartzell sells new props thru Van's to us a little over $5k. Retail they list for $8k to $10k. McCauley will no doubt want a lot for there prop. Look into it and decide for yourself.
If you found one cheap, let's say, I am sure you could use it, but be prepared for some details like spinner and cowl placement that may or may not work (most likely NOT) with Van's parts. Nothing that can not be surmounted.
I always liked the looks of the McCauley blades, I went thru the process of looking into what two blade McCauley models are applicable to RV's, and I casually hunted for them on the used market for a while. I was considering them and looked into it seriously as an alternative to Hartzell, but I came to the conclusion it was not as ideal as Hartzell for many reasons. No one reason was a show stopper, but there are many little reasons. They seem to be more rare, and as I mention cost a premium new with out OEM deals thru Van.
After calling a hand full of prop shops around the country what they thought, one or two suggested I stick with the Hartzell. I don't recall the exact reason but gather they liked working on and servicing the Hart-Z more Mac-C, may be better manufacture support, which was implied. Add to the fact it may not fit as Van had planed, since Van's "base line" is the Hartzell.
Performance, I have no idea, but I don't think you can beat Hartzell's new blended airfoil prop (BA) in anyway, price, installation ease (using stock parts) and performance. The BA was made for fast experimental's and the RV's in particular. The Blackmax no doubt was made for upgrades on Mooney's, Comanche's and other such planes. Close but not a perfect match of airframe and prop. Hartzell test on RV's with modified engines. I doubt McCauley is going after the experimental market. I talked to them years ago at Oshkosh. Their attitude was, yea sure will sell you a prop, Cha-Ching$$.
I have done some research as you can tell. Path of least resistance, Hartzell. In my opinion most bang for the buck, Hartzell, and top performance of ANY prop out there goes to, Hartzell. (Please no hate mail how great prop (XYZ) is. I think Sensenich is awesome, but we are talking C/S props.
This is based on my opinion and info I have got from prop shops and prop flight test comparisons from people like Van.) Service availability for Hartzell will be probably second to none, ie more shops nation (world wide).
What I heard about McCauley as a company (read rumor) was it was gutted in the last few years. They moved the company and got rid of a lot of experienced employees. You know, move or leave. The typical genius management moves that brought us great successes like Enron. Not saying they are going under, but they have lost experienced people. This may affect customer service? I have called Hartzell a few times and found the tech support to me very helpful. I have never had a McCauley.
Last WHY WHY WHY WHY three blades, more weight, more cost and less top speed. I know the sales pitch, even Hartzell has three blade prop "upgrades" to existing Wichita planes. Three blades are SEXY to look at on the ground no doubt. It is like a hot woman, nice to look at but they cost more and don't do a lot more, probably less.
Get a good reliable lady (prop) that may not be as sexy to look at but is not as "high maintenance" and will do more. The advantage of three blades does not really start until you get into larger HP engines (300 HP). 200 HP does fine with 2 blades and is really optimal from an aerodynamic point of view. Even 250-260hp is well suited for 2-blades. NOW there are reasons to go 3-blade, less noise and some say smoother. However there is TANSTAAFL. (google if needed, its my acronym of the week).
Recommend Hartzell BA, a steal. George