Growing style has a lot to do with this. There is no universally correct answer to removal vs. retention. Here are a couple of pertinent points. Leaves have the majority of the plant's chlorophyll which allows the conversion of light to sugars. 2. If any light reaches the ground it is a loss of potential. 3. Top buds (closer to the light source) are usually dramatically more developed than lower bud. In my experience, when I pull fan leaves I sacrifice energy to my prime growing location to allow lesser development further from my lumin source. My yield of high end bud suffers for a little more popcorn. I prefer allowing nature to work her magic.