http://youtu.be/DOeKsD8aXq0
While this may be represented as a comparison between engines, I have several problems with it. You do not fly at 0 airspeed, but that is the speed that this test was run. If a prop is optimized for climb or slow flight, it will outperform one optimized for cruise in a test of static thrust. A cruise prop could well be operating so that while the plane is still, portions of the blades of the prop are stalled. That is an apples to oranges comparison, IMO. To add, Eggenfellner doesn't have the greatest reputation for customer service. Google his name and Subaru or problems, or "customer service" and see what comes up. The Viking well may be a much better engine, but how much time is there on them out in the field?