Little bit :P, I don't doubt their ability to turn out nice buds I just think once you hit 300w+ it's better g/pw ratio to just use a 250w or 400w hps.
Personally I like to use cfl or t5 for seedlings/clones, led and/or CFL'S for veg and 400w HPS for flower, in total I draw about 800w-1kW/hr...