well nolan usually people mount above center because the center they are talking about isn't true center, at the ski shop i work at we once mounted a pair of skis above center. why the kid was fuckin dumb and ignorant so there ya go
its all about what you want if your an agressive good park skier go with AR6 if you just progressing in park skiing then go thruster, personally AR6 hands down
if your lookin for a ski to last you a couple years go k2 the top sheets on 4 front stl are extremely soft its like drilling into a kids ski (when mounting) if you want a pair for just a season then go 4 front their more fun