Buds that get light definitely grow better. I leave as many fan leaves as possible, but I also gladly take off ones that are directly covering an otherwise well positioned bud site. Taking out a lot of the undergrowth that gets no light is one of the best ways to prevent powdery mildew and other fungal issues-I'm all about air circulation under the canopy. Minimal defoliation above canopy, maximal defoliation below canopy works pretty well for me, though I'm purposefully leaving a few buds growing below the canopy, in my current grow, just to check if I'm right about direct light, because you hear people repeat that chestnut all the time. I'm also still trying to figure out how many colas to aim for in a typical 4x4 ft, 4 plant type grow. I've got one with 8 colas, mainlined, one with 12, one with 16 and one with 20+, just to compare things like yield, diameter, quality, etc.