I have a 600 in a 4x4, a super sun 2 hood. It does it's job pretty well but I want to optimize everything. A 600 in a 4x4 is 39 watts a sq foot......while a 1k is roughly 60. I think changing to a bigger hood would be best as well....block buster or raptor6. Last run I did 6 plants in 3g smart pots, I want to do 9 or 12 next....however many I can fit. Eventually after that I would do co2 but changing the light would seem like the next step. Anyone move from a 600 to a 1k? Were you satisfied?