what do you think is the more effective head the 2" 2-blade or the 1.5" 3-blade? sure a 1/2" difference but the 3-blade will give you more surface cutting area but more resistance.
the 2 blade will only be a 1/4" longer on each blade, but the 3 blade will give you a whole other blade (don't know how long the actual blade is) that will cause tissue damage.
so it would be 3 wound channels compared to 2 wound channels.