Brad...
I've test flown a number of RV-8s with various props. I've not done a detailed analysis, but the 3 blade MT climbs a little better, but who does climb at low IAS / full power in such an overpowered aircraft
The "b*lls out" low level top speed is about 6-7K less than the BA, and going from 180HP to 200HP makes little difference to that - the prop meets a brick wall, and the BA design is entirely about moving that brick wall. But again, who flies their aircraft round at absolutely max power?
Formation Loops between the 2 back the above up - Hartzell struggles at slow speed, MT can't keep up at high speed.
Finally, if you hanger in a tight space, 3 bladers are a pain / more subject to damage (as one poster above might expand on...)
One clear difference with the MT is idle drag. In Formation it can be great (like an airbrake), and for short fields it will help get you in (it might help you get out, but fairly academic). However, it could also catch you out in terms of poorer glide / energy loss in the flare if you are not careful - in the UK the RV-8 with the MT has to carry a warning of min IAS of finals of 70K as a a result.
Subjectively, there seem more "issues" with MT in terms of maint - blades somewhat more delicate and dealing with MT appears not always easy/cheap? The MT is lighter.
As a pure opinion, I would go for the MT if looks are most important. If you want a prop for propulsion, Hartzell BA
