The fallout from that thread is that GML is a shuyster and made up a bunch of shit to badmouth his former partners, HLG. So that stuff was mostly either taken out of context or simply GML lying to try to push his own brand.
One thing that’s certain over time - you don’t grow your own brand by trashing others.
HLG makes quality products, but is overpriced and not designed for a good spread of light - they’re engineered for low cost to build. They’re basically just bright and efficient. I’m not mad at them, but in our grow settings, there’s actually a lot more value in an even spread of light across the canopy.
Check out some of the independent testing and par maps for HLG lights on youtube and some of the lighting forums. Here’s an $850 HLG600 Rspec PAR map at 12" hanging height and then 18". Pay attention to the 4x4 area numbers specifically:
Here’s a similarly priced $800 basic bar style light for comparison (I’m not recommending this, just showing it for comparison) again at 12" hanging height and then 18":
Even the $1200 HLG Scorpion Diablo flagship doesn’t improve the spread that much. This is way too much light for a 4x4, but it’s not enough spread for a 5x5.
If I wanted a bright single point source that I need to hang high or worry about burning or bleaching tops, I’d grow with HPS again. When you have to hang a light really high above the canopy like that, you lose all the gains of its efficient diodes. You want efficiency and spread and total output. Of course you can get good results with an HLG, but they’re not great for the money. You’re much better off buying a bar style light with 6 or more bars, or just building one yourself.
Edited to add the pics since it hadn’t embedded them.