I was wondering the same seeing as I just got my 400w Hortilux in the mail... Dosen't it seem like the hortilux would be optimum indoor lighting, being that it has an enhanced spectrum? In my view, the closer a bulb comes to replicating actual sunlight (In spectrum) The better... after all most outside grows I see are TOWERING... and natural sunlight contains ALL colors in the visible spectrum so if you can dish out the extra $20-30 per bulb why the hell not?