I've done a bunch of
led growing with both cheap ebay LEDs and very expensive retail LEDs. I have found the main struggle with them is the trade off of light proximity to the plants and coverage area. They are plenty powerful when you can put them 6" above your plants, but that doesn't provide much coverage. For a 4x4 growing space about 360W (4) ebay UFOs seems to be enough to grow all but the most light hungry plants all the way up to cherry and grape tomatoes. I am currently doing a 4 pepper plant grow each under a 45W panel. Since each plant has its own panel I am able to keep them very close to the canopy. I am finding that this amount of light is just at the lower limit of what they need to produce peppers. Compared to my 4ft 205W T5 HO LEDs tend to grow bushier plants that flower earlier. An added benefit is the reduction of heat and all the expense that goes with trying to deal with it.