XRAY - Model racing cars

Hello,

I was just wondering what difference do the 2 hole front arms in terms of shock position have on the handling and whether or not any team drivers recommend using these arms as on the set-up sheets it does not have an option for selecting these arms. Also what is the difference between Hard and X-Hard.

Thanks

i use 2 hole arms (front). it gives effect more hard springs.
for our track i need more hard front spring, but xray don't produce spring harder than 2.9