The only time in my opinion that one needs to control stretch is in an indoor setting. With an outdoor grow you are using the best light source around, the Sun. When using HID lamps you must consider the decrease in lumens that rapidly occurs as you move even a foot away from the lamps. This is what causes the stretch; the plant is "reaching" for more light. I find that I must keep my lamps as close as I can without burning them (good fans help as well as AC in the summer). I usually turn back my lighting to a 12-12 when my girls are about 12-16". They will usually double in height after the rest of the cycle. Why short plants for me? Height is a factor as well as the ability to care for them and manage them (the taller they are the more staking and tying you will have to do), also when you have a bunch of plants all together, the sides and lower parts of the plant will not get enough light unless you are able to spread them out a bit... Shorter usually equals narrower unless you top your plants to make them bush out. As far as bud formation goes, the closer they are to that light source, the more they will fully develop. As you may also know, the particular strain of the plant effects height/bud spacing also.