I guess the thing they are missing, not all LEDs are created equal. That is the point of graphs/charts etc that makes many peoples mind shut down (mine included unless I am very familiar with it). Commercial lamps that use generic LEDs give LEDs a bad name and it will take some time to sort that out. I think I could build a decent LED out of $6 generic 100W COBs, but it would not end up being cheaper / PAR W unless I allowed the efficiency to drop lower than HPS, defeating the purpose.
Another thing I think many LED skeptics are mislead about is heat. Generic LEDs create more heat than HPS, but the highest efficiency LEDs can get the job done with as much as 5 times less heat than HPS for the same yield. That creates some very interesting possibilities, even in winter, a good size flip flop system is self heating 24 hours a day so you can grow a huge crop of the very dankest bud with no heater, no AC, no dehumidifier and very little electricity.
