One advantage is for Bike Friday split bar User , because the mount is 2 separate pieces, so remain on the Bar halves when they are separated ..

Of the other 2 I find Klick Fix, (which carradice uses ), and Ortlieb bags can also Use , is easier to remove and re install on the handlebars ,

than Ortlieb's figure 8 cable wrapping scheme ,

But Of course that is simplified by stacking 2 threadless stems on the steerer and when boxing the bike It can come off un disturbed as a Whole.