Da Rock Master Airscrew props have way less pitch then they state. measure them and compair to APC props.
you say three blade props are more efficient than two blade props. LOL dude you are way off on a three blade prop you have one more tip producing lift/drag. You talk a good game but your are worng. In fact we are all worng in this forum in that we all have read snippets of information from the net and base our own theory on those readings.

Also who cares if one prop make the most thrust on a test bench. lots of thrust and zero airspeed means nothing. We are flying airplanes they need to move thru the air to fly. So the prop with the most thrust while flying " for our desired performance" is the prop that provides the most thrust. sure your 3 blade props make those planes climb well but in no way are the best props for speed.

I will always agree that 2 blades are best but that doesnt always mean I will fly with a 2 blade set up also.
before you state why Warbirds went with 3 or more props you need to see how they were designed and what they were designed for. We can all agree to the fact that most props going past .85 mach isnt very effiecient right?

warbird fighters need lots of power to climb and to have high speeds. doesnt matter on the prop per say in that its "power" than gets climb and speed. now this added power to reach the design goals of these fighters had some restrictions. firts and foremost is prop tip speed. they needed to keep this close the .85 mach or less. a two blade prop on 2,000 hp would need to be around 16 foot in diameter to asorb that power. to keep the tip speed with in the desired range you would need a gear box added to the engine. Well this would add weight to fighter. This would take away from the climb and speed. now another reason for not running a larger 2 blade prop was that you would need much longer landing gear struts. you may think that would be easy but far from it. the longer struts would need 3-4 times the strength in the wing to handle them. this is because the struts would need to be placed farther out from the fuselage so they could retract. so they would need stronger spars because more of the weight was placed farther out from the center of the wing and would need stronger main spar.

Ok now another area with the longer struts was you would have more stress put into the main spar because of the longer struts placed more torsion on the spar. think or a 3/8 drive ratchet on a stuck bolt. its tight and you can budge it, but if you use a breaker bar ( longer strut) you apply more torque/torsion to it. So now you would need a much stronger wing spar again to hold this extra torsion placed o nthe spar which again would add more weight from the center of the wing. all this added weight reduced the speed and climb of the fighter.

So in comes a shorter prop but with more blades to asorb the power. now they reached their goal with the fighters. even larger planes that had now ground clearence props used more than two blade props to reduce weight and keep the tip speed down.

now on our models we dont care to much about noise, how much fuel they burn but care how well they fly. if a three blade prop works well for you and you like they way it flys then good its your plane and your hobby. I like two blades as i find the APC props to be the best for the price. sure carbon props maybe a bit more accurate from prop to prop but that is because they have only a few molds for each prop. APC has many molds for one size and needs that to meet the demands and to keep the price where its at. the molds are machined out of aluminium and sure one maybe off some but most of us sport guys it doesnt matter as our planes are way over powered.

by the way APC make three blade props and they use the same airfoil.

also for those wondering most props make 90% of all their thrust with on 2/3rds of the prop.