I have a 2200 Jabiru in the Avid that I crashed. I put about 400 hrs on that engine, and eventually I plan to fly it again once the plane is rebuilt. As far as props that don't move air near the hub, Warp Drive comes to mind right off the bat. I did run one without problems though. Wood props are carved/curved much closer to the center than the Ward Drive. I think the 3300 is harder to cool than the 2200 also. I haven't put any time on a 912 yet, but that is the engine I would go with judging from what I've read and heard. Lots of happy though poorer people running them. Keep your eyes open, a good used one will come along if you can wait for it. If you are just starting to build, it'll be a while before you need the engine anyway. That's my 2 cents worth, and worth every penny you paid for it! LOL Take care, Jim Chuk