In my experience the very lowest branches didn't get as much light, and the buds on them were next to worthless. I usually prune off the bottom few branches, unless they are obviously going to be thicker. I'm not sure about cutting leaves to make them grow taller (although I've heard this as well), the best thing is just to raise the lights.

I prefer taller and less bushy plants (think same amount of branches as a short plant, just spaced out more) because they seem to develop better buds as they get more light.