I have open & closed muzzled guns.I think the test result is down to the fact that the master america has a standard euro rubber that pulls in line with the shaft.A circular one can also be added.The Azimuth uses circular rubbers only so you obviously have the extra rubber that comes around the front of the muzzle.Quality of the rubbers as well as thickness & thickness of shaft plus shooting line type all come into it.
I find that the open muzzle design has an annoying habit of the line coming off in surf or when its in the boat resulting in tangles.I also find it quicker to reload with the closed.This is a definite bonus when you are dropping on a shoal of fish & hope to string a few more before they move on.I dont find this so much a problem in the med where I tend to take fewer shots & have longer(generally )between dives due to deep diving.
Where open mu
les score over closed is when using shark fin loading tabs on spears instead of notched as there is nothing for the tabs to catch on.
