The Gong Perv works very well with a 2+1 setup, and is massively better for surf or downwind. I use a 7.5" centre fin in mine. The side bites add drive, directionality, and a certain amount of extra stability. So unless you are just paddling distance
, especially in flat water, I'd recommend using a 2+1 setup. In the real world the extra drag of the side bites is usually outweighed by increased tracking and control.