I have a story for you, brother. Xtend, the branch train product had just come to market. Everyone, and I mean EVERYONE was loving the stuff. A friend of mine gave me a large 60 serving tub. I was just starting to diet for a contest. I added in about 10g (2 servings) into my diet, taken first thing in the AM before fasted cardio as well as through the day, during points of hunger. I made progress along the way, but as the tub of Xtend started to run lower, I began to use less and eventurally, satrted taking it less often. Now of course, over this period, I was also ramping up the intensity of the diet and I was slowly adding more cardio. But then there came one faithful that, that the tub of Xtend ran out. No kidding, within the next couple of weeks, my physique "popped". It was dramatic. There is no question in my mind that I was using too much and once I cut it out, I saw some good change. 

So I'm not saying that you can't get lean on BCAA, but I can speak first hand, that they are not innocuous. So use them when needed, but don't go crazy. I use them while dieting now days, but I usually save them toward the end of a diet, when I am super weak and it is a struggle to train and do cardio.