The more helical degrees you put on the vane, the more aggresive the arrow will spin during flight. Think of it as the rifleing in rifle barrel. I use a R.Hand 6 degree helical on carbon shafts. Personally I like my set up. If I didn't, I'd change it, but everyone is differant, and like something differant. That's what's great about archery, no 2 people will have the same set up. As for performance, tonight I was shooting, and got a nice 4" group at 40 yards, one time that is, several other groups were out around 8 to 10 inches, but that's me, not the bow, I ain't used to shooting that far, I was just plinking. good luck.