LED as a generic term does not equal all LED's. There are many different styles, qualities, and watt ratings of individual LEDs that vary drastically in efficiency and output. From your screw in bulbs, cheapo ebay panel specials all the way to custom built cree COBs. All LED's are not equal by any stretch of the imagination.LED's in general are more efficient lumens per watt than standard grow lights but where they get the real benefit is the spectrum of light that the LED puts out can be tailored by selecting LED's of different light spectrums and filling in the panel to put out your goal spectrum. That's the reason they have veg/bloom switches. There's been research for decades into the spectrums of light and how they effect plants. More blues veg better. More reds are better for bloom. HPS and MH lights waste a lot of their power because they put out lots of light in spectrums that don't really benefit the plants much.Some of the newest lights I've seen actually allow you to personally adjust the spectrum of light if you buy their computerized controller. These are the newest commercial lights from California Lightworks. It's not even as expensive as you might think.If you can afford an LED with UVA/UVB lights it does increase potency. You can also supplement with UV.I've seen it personally and there's plenty of research to back this up. THC is a natural sunscreen. That's why the highest THC plants that existed in nature were grown at high altitudes close to the equator where UV levels are highest. They had to be hearty and resinous to not be scorched by the high altitude sun in the Kush region. The glass on most HPS hoods blocks out 99% of UVA/UVB.Instead of putting the actual watt rating on the box many modern LED companies rate the LED by mathematically how many led's are in the array of what wattage. So if you have 44 5 watt leds they call the light a 220w led but it probably only runs at 100 watts because they don't run the led's at max watts most times half to 3/4 actual power. 3 watt led's are run at almost 1.7 watts by platinum. light says p450 but actual watts is 255.Lumens is not a good rating to judge a light by because it doesn't account for correct spectrum. That is what has brought about the PAR rating system for lights based on the light spectrum plants grow best off of.