Despite "grower" leds are on the market for almost 10 years now, there seem to be a huge part of people still have a very vague idea on how they work, good light spectrum for plants, the intensity needed for cannabis and so on.
I think part of this problem being still present is because the majority of info on growing with leds was given by led manufacturers and not growing experts or scientific measurements. There is still a lack of proper info on led growing products, seems to me the old selling practices still persist and new led growers fall right into the abyss of unrealistic claims and expectations.
And then the myths persist in the growing populations, until some numbers and reviews pop up.
Thanks to test growers and people who measure 'things' with measuring instruments we found out many scams and gems in the led world, sadly the truth is slow to spread around.
I feel there are good choices on the market today, there are way more bad products but that's the residue of those marketing lies and will be swept away in some time.
Sadly for me the price bar is way too high for good products, so the good-old(but improved) hids still have some appeal as proven technology which is available at a fraction of the led cost.
For example if I would(hopefully will soon) have to buy a lightning setup, I'd definitely choose some good hps/mh system. One can get a gavita 1000W for the same price as a GN 75W unit, to be fair these two can't compare at all in any category.
The other good option is CMH light but still has a high buck per area bar for a starting setup for me.
I feel there are two best ways to gain proper experience
1. start with hids(old school tradition), switch on leds(best on market!, avoid the rest) or the best hids(phillips CMH 315)
2. get into science and get the numbers, one can use theory to understand almost anything
The third way is even better, it's combining the two from above
I really would like to see some more numbers from led manufacturers, last time I searched for MarsHydro data and it's so discouragingly confusing that I would never consider buying anything from them. Sadly also GN don't provide with such measurements, but I'm sure once the light gets on the US market, someone will do it and post a video

Like what the MonsterGarden guys do, that's a really good practice.