I currently own a nightforce 2.5-10x42 in second focal plane but am looking at other scopes and everyone is telling me to go strictly first focal plane and I dont rightfully understand the difference and if I do from now on get only first focal plane how confused will I be when using this second focal plane scope? Furthermore, I was told that a second focal plane scope is only accurate on max power, is that true? if so, why? help me out here, i am new to the game......