i just grew a pair of incredible bulk fems recently, one under a 600 watt hps, and the other under 200 watts of quantum boards, run at 43 volts, 4 amps. the plants grew very differently, which i expected. the hps plant, in a 20 gallon tote, stretched in the traditional fashion, gaining about 40% in height, and yielded just over 7 oz dry.
the one under the quantum board only stretched about 10%, but was fuller, and had a very even canopy that i had to do very little to achieve. it was in a 10 gallon tote, yielded just a hair short of 6 oz, and had very little larf, the buds were nice and hard and at least thumb fat all the way down. it also took a full week less than the hps plant.
so as far as i can tell, they're about even. you get a little more with hps, but it takes slightly longer. you get a little less with QB, but you get it quicker. the quality was about even, the hps buds were a little larger, and while they were no means loose or airy, they weren't quite as hard as the QB buds. the equipment cost seems like it would even out pretty soon too. the boards cost twice what the hps cost initially, but will last at least 5 years before they'll need replacement. i use a blue corrected bulb that cost 70 bucks in the hps. i replace it once a year, so after 3 years, it equals the cost of the ballast and cool tube, making it equal to the cost of the QB.
this is all on a small set up, on a larger, commercial scale, i'm pretty sure de hps would still be the way to go, but if you're talking about people growing on a personal level, i think ones as good as the other.
