I have two separate grows right now. Same strains, nutes, soil, environment, but the lighting is different in both rooms. One room has a Spectrum King SK602GH and the other has a hortilux 600 watt conversion bulb. So far the LED is doing the better job, but I believe I need to do a few more grows to rule out any problems that may occurred that I wasn't aware of. So far, I haven't seen any problems with the exception of a over-fert on Ayahuasca purple, but that was in both rooms. LED is currently packing on more weight and the plants look like they will finish faster than the conversion bulb. I may try a hortilux 600 HPS in the next test. The only problem with LED is the cost. I'm over $2,000 on my SK602GH whereas the HPS is much cheaper, but with the cheaper monthly LED operating costs, it will eventually return investment. In any case, from what I see so far, the LED is winning slightly. Few more grows will let me know which way to decide. Both are great!
Happy growing.