It's a subject of frequent debate whether APC or Master Airscrew is better. There's a common theory that the flexing of MA props makes them inefficient. It's also common for people to put comparable size MA and APC props on an engine, tach them, see that the RPMs are higher on the APC, and then conclude that it is more efficient. Are they really more efficient, or is it just manufacturer hype? In the end, it doesn't matter for this discussion, because efficiency, real or perceived, has little meaning on a trainer airplane.

On the other hand, it's widely felt that the sharp tips on the APC props make them more dangerous than MA props. I find the MA props to be more durable, and with the wider tips, a bit safer.

Personally, I use both.