I agree that the LED grow light market is filled with BS. However, there is compelling evidence, such as presented by yourself, ledbudguy, that the technology can work. So then what should we look for when choosing a light:
1. Higher Wattage for diodes. Today 3w+
2. More spectrums. Today 11 spectrums
3. Enough total wattage to cover your core area. This is the tough one, since manufacturer claims here vary significantly. Ex. ISIS FX-3 coverage is 100 sq feet. A 100, really? I wouldn't want to waste all that light outside my 4x8 area...
4. Lens angle. 60deg or 90deg??
The rule of thumb for HID lights is 50W/sq foot. Can we even come up with one for LED, since the wattage can be spread through a large surface area on the panel itself, where as HID has a concentrated source of power?
I agree that the coverage area is highly exaggrated by all of the manufacturers... in my instance, I would feel comfortable reporting that the ISIS-1 that I am using is good for 4-6 plants of average height. I'm pretty sure they have the spectrum figured out at this point in the game, although we can probably expect to see developments in the area of mold supression and insect repelling...
To answer the questions, I would say that...
1. Absolutely don't buy anything that doesnt have at least 3w diodes in the flowering spectrums
2. I think that the 11 spectrum is probably better than the 5 spectrum that I am running because I know for sure that the 5 spectrums produce wicked bud
3. You see here all the fixtures that the companies are selling are all based on the same configuration of diodes, the only thing that I can see that changes is the size of the case. I would'nt expect that FX3 to realistically cover more than 20 sq ft if you are growing weed. Bottom line, more wattage doesnt mean more coverage, coverage is determined by lens angle which takes us to the next question...
4. If you are growing lettuce I would go with 120 degree lenses, in our case marijuana I would stick to 60 - 80 degrees of lense angle. That said, I have figured out something cool with the interlacing of the spectrums of different angled diodes. The interlacing of certain spectrums appears to have a pretty amazing effect!!! I'm trying to put together some cash and maybe get one of these manufacturers to donate some gear for research so that I can set up what I believe will be the grow room of the future.
Like I said before, don't believe the hype until you see it first hand from many independent sources... Any dickhead out there can say he has the best grow light, and until it's proven it just bullshit!