I know that product, I saw it on display 6 months ago at an hydroponics store not far from my home. But they removed it from their display recently because they were not receiving good feedback from growers who tried it.

This lamp is targeting the "supplemental" light market for greenhouse and it's focusing on a limited spectrum of blue (455-470nm) and red / far red (660nm and 730nm, not the usual 630nm orange-red that doesn't activate the phytochromes required for flowering). That's the main problem with most LED lamps when used as the main source of light: they only target the absorption spectrum of chlorophyll in the blue and red spectrum. While it's an important one, it's only ONE of the many pigments that need light with various wavelength (color) in a plant in order to be healthy. Leaves don't "change" color in the fall, they only loose their chlorophyll pigment first (it's unstable) and the "underlying" yellow / orange and red pigment are revealed. Lettuce might only require red light to grow, but most complex plants will require a more complete spectrum in order to be healthy. So in a greenhouse where a plant receive natural sunlight for part of the day, the narrow spectrum of a supplemental light is not a big problem.

For photosynthesis alone, their product is really the equivalent of a 600W HPS with far less power consumption and heat generation. In lumen, since it's targeting part of the red and blue spectrum our eyes don't perceived as bright, it will seem "dim" to the human eye compared to the output of a HPS 600W , but in term of PAR, it will be the same for the plant with only 200W. So you'll save a lot on electricity and when comparing price, keep in mind the LEDs will only start to fade a little after about 50,000 hours (that's 11 years at 12h a day).

Because of its narrow spectrum, I would not recommend using this lamp as the only source of light, I would "supplement" it with complete spectrum fluorescent tubes or CFL in order to make sure your plants receive all the light wavelength they require to be healthy. If you want to go "all led", another approach would be to add a mix of warm and cold white LEDs in the mix (there's a lot of them available in many formats that you can "plug" into a 120v "normal" light bulb fixture.

There's another less expensive (but less powerful, with 90W) new LED lamp out there from HIDhut. However, I don't think they have LEDs that reach the 660nm far red spectrum required for triggering the flowering phytochromes (from what I understand, they use 630nm orange red with some blue led). Here again, you would have the same narrow spectrum that could be a problem for a lot of plants without sunlight or another lamp with a complete spectrum.