As have i but 2 things, why would you want to look unbalanced and like crap. I get more compliments from women on my ass and legs then i do anything else. and second, why do things the hard way? Sure you can train only upper body but it will takes years to achieve what you could do i probably half that time training properly by exercising your whole body. Your body is meant to be in proportion, do you really see THAT many people with chicken legs or huge legs and no upper body???