I started out with my first grow defoliating-- it makes sense, right? Get the buds more light.
But the more I've researched, I've gone back to keeping them on. Aim, your explanation was perfect I translocation is the key. But there are two points I wanted to bring up that I dont think have been mentioned (again, haven't read it all).
1). For those of you defoliating, do you remove a fan leaf that is on the top of the canopy, to reveal bud sites that are a foot lower than that leaf? (If you train for multiple tops like I do, then the tops form around the outside, like a ring, around shorter growth in the middle). What type of light are you running? A 600 watt? A 400? Even in a 1000 watt light, the lumens depreciate rapidly the further the distance from the light. If you remove a large fan leaf that is at the top of the plant, to let the leaves/buds at the bottom to get light, they are not going to receive any where near the same amount of lumens, or be able to produce near the amount of sugars that the fan leaf could produce for the plant. Trust in translocation.
And 2). Has anyone ever heard of RAW? Ya know, products that add carbs during flower? This is all to attribute to a better TASTE. Where are the carbs/sugars/starches created and stored in a plant? In the leaves, especially the fan leaves.
If you are a fan of great tasting smoke (I'm only headed into my 3rd grow, but ive tried both ways and noticed a significant difference, especially when it comes to keeping that great smell through drying and curing) then leaving the fan leaves on will make a big difference.
Its crazy, I had two plants from my first run that were bag seed (from the same bag). Very similar phenos, 1was defoliated and 1 was left alone. The difference in the smell and taste after drying and curing was unreal. It made me a believer in the plants ability to do it's thing without me taking too many of its parts off.