With the high pull versions of the lift you'll find two sub variations. Some like to pull the weight very high. Others, and I fall into this category, use this lift to improve the full snatch and train it heavier than the snatch. This means I don't pull the bar to the chest, I pull it past the point of explosion where I am fully extended on my toes with shoulders shrugged. The bar becomes weightless, floats up slightly, and then returns itself to arms length upon which point I reset for another rep or finish. The positive for this this method is that the weight is greatly increased (that last extra foot of explostion is a damn big foot). The benefit of pulling it higher is that when dropping under the weight in the full snatch you pull yourself under so this enables a bit of training on that last bit but IMO the pulling is totally different so I don't see a lot of sense in it and I haven't read a compelling explanation from anyone else.