A valid point, although I don't think that there is any true practical limit for the height of depth drops. After seeing the research that says that the higher the box the better training effect, I thought ok, so high is good, but you still can't go too high. Then I saw the trick ski jumpers at the Olympics. Those guys jump off a ramp and go like 50 feet in the air while flipping, etc. and land, some with hardly any compression. Obviously you have to work your way up, but if you've got the balls to do it, the higher the better.