I dont mean to be rude or anything but i think some people are kinda missing the whole point of this thread. I know that there are way better lamps than CFL's I KNOW THIS. BUT for the space that i have got to work with CFL's are my only option as i have already said. I dont know as much as some people about plants which is why i was asking if it would be better to grow my plants tall or short. As i am a noob with plants i thought that growing them tall would be better.
well you're right on point...the bigger the plant you grow the bigger the yield will be in the end...the smaller the plant the less yield you will get.
however to grow a big marijuana plant you'll need a BIG powerful light (ie. hps/mh) cfls work for growing (i used 10 23w cfls to veg for my first grow)...the growth was stable but not very rapid...only about an inch and a half at best a day...i picked up a 600w digital hps system and was able to push them about 4inches a day...over two times better/faster than cfls.
so since cfls are what you're going to have to work with its best to keep them short so the light can penetrate all areas of the plant...if you put a 5ft plant under cfls only the part where the light is will flourish...the rest will be fluffy buds and weak/slow growth.
if you do use those 2 giant cfls i'd advise maybe getting a few 23w cfls in either 2700K (produces a red/orange light) or 6500K (produces a bright blue light)...those two kelvin (K) ratings are ideal for marijuana plant growth. hps = red/orange light...mh = blue light...
so as long as they are 2700K and 6500K you'll be fine (or near there).
hope this helps.