I've used the hydro grow led's since last August and I'm pleased. As far as gram per watt I achieve much better results with the LED's than with my HPS. However, they do cover a much smaller canopy so you really need a bunch of them, which may be cost prohibitive initially for people growing in a larger area. Over time they will pay for themselves in savings on bulbs, utilities, etc. They also seem to grow really happy and healthy plants. I would love to have 40 or so of these lights for my new 12x20, but there's no way I can shell out that kind of paper, so HPS it is. I WILL however still have a continuous aero rack under the LED's for my personal stash because I believe they grow superior, heavily resinated, quality bud. My last two cycles I ran soma sour diesel with 9 plants under two 600's and 8 plants scroged under my 4 126 watt LEDs. All were in aero/nft rails, all on same nutes schedule. The LED run was just over a g/watt and my HPS was about a half a gram per watt. However, the sq footage in the hps tent was almost double that of the area for the LED's. Hence, if I could afford to cover the entire ceiling of my new room with LED's I would.