some say that the 600 is a better go than the 1000. wouldnt the 1000 be better because its bigger? or is the 600 better because its doesnt put off as much heat so you can get it closer to the plants for deeper penatration? the room is maybe 4.5x4.5. i know you want more watts per foot but is there really that much difference between the 600 and 1000w?