You won't be sorry, 71.

In addition to the extra loading a third blade puts on the engine, there's a matter of efficiency. Three blade props are not as efficient as two blades, and smaller props generally as not as efficient as larger props. If a prop turns too fast, or a blade turns in the turbulence of the preceeding blade, it may it cavitate. This absolutely kills pull and speed.

You're right in a previous statement you made. Prop selection is VERY critical to the flying qualities of your plane. All props are not created equal. A 10-6 from one company may give completely different flight characteristics than a 10-6 prop from another company. In the sizes we're discussing, I MUCH prefer the APC brand over any others I've tried. They're a tough prop and seem to be very efficient. Even though it may cost a little, try different sizes and brands until you find one YOU like, then stick with it.

Dr.1