There is lots of folklore re props, particularly APC & MAS props -- & lots of it is wild conjecture.

To begin with, APC props don't always give more RPM than MAS -- often enough a MAS prop will out-rev an APC. That is no indication of anything other than a particular prop on a particular engine will give a higher static RPM -- not more thrust. Nor is it an indication of in-flight performance, because different props have different flexural stability & can behave significantly differently when unloaded (in-flight). Additionally, engine power characteristics have a huge impact on prop performance, & vice-versa. An engine-prop combo that gives high static RPM may not work particularly well when unloaded in flight -- due to both engine & prop considerations. The converse is also true.

One thing is certain -- because of the construction material, APC props retain their design shape more accurately under load than MAS props do. That gives APC props a better chance of consistent performance.

WRT the blade shape -- high aspect ratio props, just like high-aspect wings, are more efficient than lower aspect ratio types -- they have lower drag vs the lift developed, meaning that less engine power is wasted in blade-drag. Similarly, narrow tips generate notably smaller tip vortices, & hence, less drag & lower lift-losses due to high-pressure air recirculation to the low-pressure side of the blade. Thin tips also have less frontal area, and again, have less drag & lower power losses. A long skinny tip can easily be doing as much effective work as a wide blunt shape.

For sure, trying to judge a prop's performance potential by looking at its shape is not a very profitable expenditure of time. The real criterion is how the engine-prop-airframe combo works IN FLIGHT. Sometimes an APC varient works better than a MAS, & sometimes it's the other way around.

Suck-it-and-see.