good luck, I'm getting about fed up with this site, it's been taken over by a bunch of smalltime DIY nutcases. No matter what light you buy they will tell you it is just a bunch of crap and they can build one much better. Doesn't help you, doesn't help me.
Where are the bigtime DIY nutcases?
Just kidding, but your statement on "no matter what" is untrue. Efficiency for a typical Chinese LED will be somewhere between 35 and 85 lumens per watt. I'm not saying it's without exception but if there is an exception I haven't seen it. Some Chinese lamps might reach 90-100 LPW and there are some non-Chinese lamps using Olson emitters touching around 100 LPW. Prior to the advent of COBs there were two companies that surpassed these typical cost effective solutions and used top bin Cree diodes. Apache Tech and Area 51 have both offered/offer single diode based lamps that probably rate in the high 120s. Now that there are COBs available other companies have joined in. Vero 29 based lamps running at or near nominal current emit 130 LPW. That would be Optic, Area 51, and Heaven Bright, that I know of. Another company Pacific Lighting Concepts as well as Area 51 will soon be offering a CXB based lamp with even higher efficiency. I don't suggest the Cree based lamps from Optic because at the higher currents there's no justifying the additional cost for minimal gains over the Vero, though others may have their own opinion.
Anyway what it all comes down to is that all those Chinese companies are borderline selling snake oil. You can't look at the watt rating they advertise in big letters, you have to check the specs and find the "wattage used" which is always substantially less than the claim. Watts x efficiency = light output. So that $200 lamp that's called a 600 might actually use 240 watts. Considering driver efficiency is probably low we'll guess it's about 200w output. Assuming 80 LPW, that provides 16,000 lumens. And Peeps are going to put that thing in a 4x4 expecting it to replace their 600w HPS. Funny thing is despite the claims, it's much less efficient than the bulb!
They would need about 1000w of Chinese lamp to come close to replacing a 600 watt HPS. So now you need to fit 5 of those lamps in the 4x4 space and it's costing $1000 to replace the HPS, along with using 400 more watts and generating a lot more heat. Not recommended!
DIY offers better quality components and uses half the electricity for about the same price.
Pay a premium and have someone else build it.