Have you ever watched Luis Mosquera snatch over 140 kilos on international stage? It is something of beauty, and it takes no slowmo camera to realize he is bringing his feet up almost 3 inches to shift them. Then you can watch Tian Tao on the same world stage clean and jerking 210 kilos almost any day, but those feet barely even come off of the ground. They seem to be performing just a simple sliding motion. Which is most optimal? Obviously, each style works, and on a very high level. Both of these can develop certain problems within a lifter, but more likely they will come from kicking the feet up too high. Not to say that bringing the feet up high in the turnover is wrong, but if the elevation of the feet is over 4 inches it is likely zapping your lift of a few kilos. An easy way to fix this problem is tall snatches and tall cleans. These are easily performed in a barbell warmup.