Top hole reduces ski pressure. Bottom hole increases pressure. That's what I understand anyways. I've also heard the bottom hole will make sled tippy. Quick to move the bolts and try to find the setup you like best.
What are you looking for? I played with shock pressure a bit last year and found my happy spot. Works good in the trees for me.....bit light if you're jumping but I don't do a whole lot of that. Seen some guys move to the bottom hole on the rear to help wheeling while climbing. I got it where I liked it with shock pressures
My numbers won't work for you as there are too many variables. I would have never thought it would be so sensitive but it is. I went to the Skinz site and they have a video series on shocks, I found some stuff there that helped me. In the end I found softer was better for me. It does make a huge difference when you get it right.