"The Supernova clearly outshines the UFO LED grow light with three times the brightness, while still only using one-eighth the energy consumption of a typical HPS grow light with a comparable output, providing enough high lumens lighting to cover a five foot by five foot growing space. "

Sounds like marketing since I'm not aware of any horticultural HID bulbs running 270*8 = 2160 watts. I know of a few Xenon projector bulbs running that range but they most certainly aren't HID, they're bare-electrode arc-discharge, and they're not meant for horticultural use (though they could be used for it.)

Also wondering how they're getting much of any lumens rating when they're dealing with monochromatic light that isn't weighted by the lumens used for illuminance, because lumens is weighted at 550nm - green. I don't see green bulbs in there.

The only good thing I see going for that panel is the adjustable red:blue knobs.

In the meantime, you wouldn't want a single panel anyways. Better to buy yourself a couple of cheaper 120-150w units and spread the light. Smaller panels spread out provide better coverage than a single panel in the center, plus better canopy penetration because of all the spread-out points of emission hitting the plants from different angles.