If you go back I think like 1-3 pages in my journal, I posted photos of all my past grows under 1000w of HID.... visually at this time I have to say that the LED grow is keeping up with and possibly even producing more than the HID setup...
My tent is considered a 2x4 tent however it actually is bigger than that... its 2.5x5'x7' so it is slightly larger than a regular 2x4 tent. I have to say that the 3 lights is perfect for the space, but more light is better
lol Its not like nutrients where more is not better, with light, up until the "light saturation point" plants can use as much as you will give them (temp and CO2 allowing).
I think LED technology as of today is as efficient as HID technology and in some cases even better. What I do know is that it usually takes about 60-80% LED watts to eqaul HID watts, meaning that if you have a 1000w HID system, you should be replacing it with at least 600 LED watts or more to get similar results (depending on the actual LED and chips used). I definitely think these LED's are MORE efficient that HID systems and do not plan on using HID again.... LED not only is effiecent, but it produces more terpenes, resin, trichomes and higher thc content as far as test results I have reviewed. So not only can you grow equal crop yields with slightly less energy, the overall product is better IMO.
As far as the plants liking the spectrum...its seems that they do
I have huge chunky frosty buds just gleeming back at me when I open my grow tent, so I think the spectrum is good according to what I am seeing.... is it optimal...nobody can answer that question, not even scientists...because each plant, species, even phenotype uses light differently so I don't believe we will ever reach the "perfect" spectrum, but I think these Intelligent Gro's offer a great spectrum that covers the full blue region, as well as a pretty broad red area as well, so it does cover all the key points for photosynthesis and other carotenoids.
I think if LED is used correctly, and given at least 60% the watts of the HID you are replacing, then the results should be very similar if not better.