You should check out the defoliation thread.
Bottom line is that you must decide for yourself.
Plants grow more leaves than they need because in nature they are constantly being defoliated by the elements and by organisms. This behavior can be capitalized on by indoor gardeners who have limited lighting. By removing a single leaf that is covering a bud site you will now allow four, or more, smaller leaves to absorb that light. There is no loss of energy manufacturing as incorrectly perpetrated by the opponents of defoliation. They just can't wrap their heads around the fact that there is more to growing bud than fan leaves.
These are the same people that would rather remove a bud site than a fan leaf. They grow lettuce.
Defoliation methods are similar to LST methods in that more direct light will reach the internode branches. This will allow these branches to grow out to be healthy bud sites. I can post some pictures in a bit to show you what I'm talking about (that is if I can find my damned memory card!). It takes 2 days or so for the plant to rebound and replace the lost leaf mass, so that 48 hours after the trimming your lower branches have already over-compensated for the loss of the leaf.
Many people ignore the impact of hormones on the plants. Beginning early on with defoliation you will strengthen the plant against stress as it has been conditioned to deal with the growth/stress hormones that are released from the removal of leaves. These hormones play a HUGE factor in the overall size and shape of your plant, and this is another point the opponents of defoliation fail to recognize as a beneficial factor.
Many people raise what I consider to be the equivalent of Veal. Small plants, pampered and babied to keep soft. What I propose is more of a Barcelona Bull that has been run and worked out. Big, beefy.
In time (not much of it) those lower branches become fully established and will produce fan leaves of their own. So you can use the enormous leaves of the main stalk, that require an excess of energy just to keep themselves cool and to transport energy and nutrition in and out... Or you can use the smaller and more numerous fan leaves of your lower branches that require less energy to stay cool, or to keep themselves healthy.
I promise you. Anyone that speaks out against defoliation has never tried it. Anyone that is pro-defoliation has tried it and won't do it any other way. Ultimately it is up to the grower to decide if they want to add another week of veg life to really fill that plant out or if they are just looking for a short stick with a bud on top.