pot sizes are the most important factor for plant size. back when i was new to MJ growing i did some dumb things.
the worst was leaving my plants in a little planter thing (the little 6 space thing that holds flowers at home depot)and not transplanting them for a month. they were trapped practicly and they reached a height of 5 inches MAX, each space used about 6 cubic inches of dirt. i then transffered them into pots of various sizes. the ones i put into a big 3 gallon pot Grew way faster and bigger then the others. to be exact about 2 weeks after i had transfered them i saw very noticable differences, i keep track of my plants growth so i can tell you that the one in the smallest pot grew inch taller over two weeks and a lot wider, but the plants in the large container grew 2.35 inches. so pot size REALLY counts.
in this case the bigger is always better!!