I don't do em. Just another damned machine, and another reason to leave the machines alone. They are, Mostly, and I repeat, MOSTLY for those that want to be seen moving alot of plates, or have some sort of fear or need a crutch. Unless of course your gym just sucks ass and doesn't have much free weights. Machines...one size does not fit all.
Every once in a while I might load it up to do calve presses, but I usually use the other coat rack, aka the Smith machine to do those.
Leg press.......And why?
I see guys everyday that can leg press 20 plates, but can barely squat down to get their freakin' gym bags.