Take what he says with a pinch of salt because he speaks out of context with advice that serves a different agenda. In another topic he linked wiki information stating that spectrum plays far less a role than was thought, in turn, light intensity alone seemed to be the bigger factor. If that is true, leds turn more W to light than cmh or hps. From that, use logic, you can see the contradiction in his defence of hps spectrum. This could be backed up with the amount of growers who swear that they now use less W of led and get the same yield they did with 600hps, but ofc that doesn't make it fact. Stay on the safe side, swap out W for W.
If you really are not sure, then maybe think about getting a 315cmh for the middle (open hood) and then make up the other 300w with some small led boards to go around the cmh in a square like manner. If spectrum is the deciding factor cmh has you covered, if intensity is the deciding factor, the leds turn more W to light so they have you covered.
People like kingrow are the peter pan of growing, afraid of change.
Those would do ok but the further away you get from a level canopy the less you will begin to yield if you don't customise the light angles properly. It's easier when possible to run a flat scrog since you then only have to concern yourself with light height, but it's certainly not the only way to go about it. You just need to understand the limitations of led, just like you don't put a 600hps 1 inch from canopy.. you don't try to hang leds above a highly uneven canopy and expect good results.
I am not trying to sway you, use hps if you want, just giving you some balance to make a more accurate choice. I would personally still use it but not before cob and cmh. The frost increase was more than noticeable, maybe that's from more light for W or from spectrum.. dunno.. but I know what I see.
