With the rule of 100w per plant, yea, 100w is better. I guess you can grow with a 75w... I myself am getting 2 80w CFLs soon
Yeah, im having concerns with the wattage of fluros, went to hardware store other day and the fluro's they sell only go upto 30 watts, and thats on a 2ft strip lamp. I figure id need like 3 of these for anything decent.