I bought a 400 watt system first then a 600 watt one and to be honest I am still sorry I bought the 400 in the first place instead of the 600. I also buy all my bulbs from 1000bulbs.com. Jmo
bulb brands are meaningless, buy cheaper bulbs and change them more often, imo, but between 600 and 400, no contest, 600 all the way, more power for you dollar than 400's or 1000's
Frick that buyem both ! Ifin yual gots the money. Mine as well make it an evem thousand watts total be bring total yur harvest up to. Good luck yur choices friend hope yual do well, with this crew helpin ya sure yu will do just fine.