With an untouched plant, energy is focused linearly. When you use LST, you are distributing energy evenly across the plant, encouraging more shoots as you know. So now energy is not focused in a linear fashion any longer. It is distributed. So instead of the plant cannonballing upwards, energy is shared amongst the varied shoots, hence you end up with shorter branches, nodes more tightly spaced, which makes for those lovely 'compressed' colas we all like to see. You must remember that bud-mass is DIRECTLY proportionate to root-mass. This is the ONLY reason Hydro sometimes yields more, roots grow completely un-inhibited. So in an ideal scenario, one would like to let a plant just grow upwards with as much root-mass as is possible. Unfortunately for the indoor gardener, a 3-metre plant is not always an option. Lighting becomes an issue and bud quality suffers. So what you are noticing is truly the ADVANTAGES of LST