Propping is 50% theory, 50% experience & 50% opinion. Which tells you that it is as much suck-it-and-see as it is theory.

I tell my students to use MAS prop because they are reasonably tough & performance doesn't matter much with a trainer.

When the going gets tough -- it's still cut-&-try. It is VERY dependent on airframe configuration, engine characteristics, altitude, temperature, & end-use. In orher words everything is important & everything affects the choice of a particular prop.

I generally prefer APC props for performance applications, but not always. It depends on --------