The p10 lifter has a small plastic piece under each binding component to raise you higher above the ski.  This helps to give you more leverage when you're carving.  For example, if to make a certain turn w/o lifters you need a 15 degree lean in your legs (from straight up and down), with lifters you would need less lean (like 10 degrees.)  BUT, and this is a big BUT, lifters suck for park skiing.  They make you less stable on landings and rails because you are sitting higher above the ground.  It's a lesser version of comparing walking with walking on stilts.  Go with whatever is cheaper because the lifters can be removed, making the binding a regular p10.