Io ho trovato molto utile la lettura di questo:
http://www.bolly.com.au/1998%20Bolly%20Book%20v3.pdf
È un volume edito dalla Bolly, una ditta che produce eliche (anche full size) e che spiega in modo chiaro le differenze tra le bipala e le tripala e più.
Quello che riportano è questo... se non mastichi l'inglese google da una mano:
Contrary to popular belief, multiple-blade propellers do not operate in severely disturbed air from the previous blade (when in forward flight). The reason multi blade propellers often appear inefficient is the need to use considerable lower diameter propellers (in comparison to 2 blades), for the same horsepower available. Diameter for diameter, a well designed 4 blade prop will in some circumstances perform better than the equivalent 2 blade propeller.
It is rare (if not impossible), to find an efficient 3 or 4 blade propeller manufactured from nylon based materials. The reason for this is the most efficient shape (thin, narrow blades) for these propellers is difficult to produce in anything but a carbon or glass composite construction.
Nella sostanza, a meno di non utilizzare materiali pregiati, i vantaggi non ci sono.