Replying to Mounting my Line Elizibeths

I have line elizibeths and PX12s for this year and I am pumped for my new set-up. However, I don't really know where to mount them. Some people have told me to go for dead center, while others have said to go way back. I will be using them for everything. They will be my park skis, my powder skis, and my all mountain skis.I'm just not sure if I want to mount them exactly at center or go a few centimeters back. If you think I should go back, how far should I go?

Basically, where should I mount lizzies that are being used for everything?