Besides the people who turn the lat pulldown into a row. I see more people doing full ROM on lat pulldown but not pull ups. To many people either don't go down all the way or don't pull all the way up. The classic chin extension to make people believe they got a full rep. And it's ok to cheat but I feel when people seem to cheat on chin ups they are only worried about completeing a rep rather than the muscles that are supposed to be working.