Im going to have to disagree with the concept that led lighting requires a more advance knowledge of the nutrient needs of marijuana plants or that led lights require more work for the growers and tenders, there are some advantages to both systems and they are vastly different in terms of light colors heat signature and light output, but just growers have to adapt to the weather when growing outdoors in many different climates the difference between the two lighting systems is minimal in comparison. I think the reason many growers shy away from led is simply nostalgia and habits, we are creatures of habit by design, if something isn't broken why fix it? the big led light industry would like for everyone to believe that more is possible under their grow lights and in some cases may be correct but as a blanket statement that simply isnt true. and I have grown small private grows using both systems and there is a difference, but nothing a competent grower cant over come. The big picture of lighting comes more into focus when one attempts to grow say a cantalope to fully ripe under either system, the leds just dont do it. its is the abundance of light that come from the cmh and hps lighting systems that make them preferable, yes you can grow weed in the shade, but it takes longer you'll have more problems and is more expensive in the long run. growers not just master growers but growers overall would prefer to remain comfortably in the chair they have chosen,,rather than get up walk around and attempt to find a comfortable chair. it is just in our nature to be this way.