cent rear skid and front shock preload

[Koke1]

I haven't touched any suspension settings on my 13 xtx. From what Ive been hearing alotta nitro owners back off the springs on the center and front shocks from factory is this true? I did noticed the my center shock is set super tight with alotta room to back it off and y fronts are about dead in the middle on the threads. if I back the center shock off will I get better weight transfer or worse? and will I see a little more top end speed from backing everything off and lowering the front a bit?