Led are supposed to last like 50000 hours with only like a 10% degradation. Their high initial cost is supposed to be overcome by never buying replacement bulbs and lower power consumption. I've yet to see an led grow that truly blew me away. But they are almost always journals done by some noobs that fucked something up somewhere along the way. There's been literally 2 guys I've seen with start to finish led journals that were impressive but they were pulling some pretty heavy wattage still.
Ive got one runnin i plan to finish several times! haha
As for LEDs they also throw such little heat that i already know im going to be using at least 1/2 as much electricity from my AC. Ive already taken out almost 100w worth of fans i previously needed for cooling my CMH/HPS lights.
I recently took out an intake fan i had hooked up to the window because it used to have to cool my hot 400w and 600w ballasts on top of my 400w cmh bulb.
And its still almost too cold for my liking in there.
Ive always felt like heat and spectrum was the main reason people switched.
Everyone knows a "300w" panel that is claimed to replace a 1000w isnt going to do that so those claims get disregarded.
But with the same 1000w of power, replacing it with leds can get you the same or better yield and use less money on cooling your room down.