No idea ive never grown an auto but lets go with the approximation of 600 grams per sq meter for a photoperiod consistently. Id say that that's a pretty good achievable yield and would work out a gram per w if using a 600W in a 4 x 4. So achievable but not easily so.
If you want to argue how good blurple LED lights are then perhaps visit the LED section. LED people upgrade and spend the $$ on their lights for good reason id speculate.
It just goes to show you don't really know much then about led,
I grew auto pounder under a 300w cheap led panel that retails at £60- about $90 or so.
This light gave me around 115w in total output and I got 113g from that.
I now have a bigger grow space and have stuck to 1 plant still.
Grown Dwc, and now with the same 300w and a very cheap 600w which cost £47. Around $70.
This plant is big, on growing experience I will pull around 7oz, which is 196g.
If I up my bucket size I would get even bigger plants, as I have tested bucket sizes from 10ltr to 25ltr and I've had noticeable differences just from this.
I don't really see how there is a comparison and like I said led are expensive in America because you put all these acrylic logos all over them eg TERMINATOR.
It doesn't make the light any better, but if you can't get these cheaper led panels in America then that's unfortunate.
My setup cost me in total £200.
Hid light and ballest in uk cost about £60-£70.
But then I need to buy carbon filters, and exhaust, ducting etc.
Hid lights because of the heat generate more smell from the plant.
I get smell in the last 3 weeks at the most, I gave a fan pointed at the lights to push warmer air to the top of the tent as heat rises, then the dehumidifier as you know conditions the air and I have customised the filter in it by adding the carbon membrane in to it.
So my air and smell is being filtered through the dehumidifier, and it works.
You stick to your hid as they are possibly cheaper for you than me.
But don't tell you need these so called high end led to grow, the companies in America are ripping you guys off. Seriously.
So, each to there own hey.
Oh and by the way your arguing with me about this not just me.