What does watts have to do with anything? The entire debacle around LED is the quality of diodes etc, not wattage. Otherwise wed all be buying cheap ass shit off ebay. 5 minutes in the LED forum gives you more than enough information to understand that there is a hell of a lot at play, not just a number.
I've no experience in LEDs but ive a hell of a lot of experience in computers, and there is a reason that chinese brands seems to be able to offer more for the money, because they are typically crap! I eas brought up almost from day 1 with the phrase "made in china" and from kids toys to electronics, it has almost always held true. Buy cheap buy twice.
Think things through more man...
Actually watts have a lot to do with it. The reason why people like to say watts don't matter is because there is so many different efficiencies being used across the board...led, hps, cfl, everything is a little different.
But that does not mean that watts are useless...just not created equally. They correspond to an output potential based on the efficiency.
Another way to look at it is
µmols/w...and top bin led's are matching or exceeding even double ended hps(gavita=1.8µmols/w) by putting out 1.8-1.9µmols/w.. A cheap chinese chip/array could be as low as .7µmols/w. Notice how watts are an important part of the equation.
And when he is saying that 8 cxa's pulling 256w@800ma(basically 46-49% efficient) isn't living up to what light@what watts? Watts matter... specially if you know what you're talking about and use the efficiency of each source in your judgements.
You'd be foolish to expect cree cxa like results at 1/6 the cost though.
But anything above 1g/W is nothing to sneeze at if the price is right.
You're missing my point. If he is getting 1g/w with epi's...then he will improve by going to cxa or even veros. It's the physics of it that no matter what people say...you can't disprove/alter physics. The better chips put out more light/watt no matter spectrum it is or whatever. More light(from greater efficiency chips) will equal more yield.
Also people get 1g/w with cfl's and T5's. Not everyone...but it happens quite a lot. Again....not every grower is the same. By your logic if he is getting 1g/w than anyone can...which we all know isn't true.
Another thing I have been dying to bring up...
g/w is getting somewhat useless. Sure people are hitting over 1g/w...but are the maximizing the space??? For reference...1000w hps can do over 60grams/sqft in a 4x4...even at .8g/w it still hits 50g/sqft. So if someone is getting 1g/w@25w/sqft, great but...they are still a minimum 100% away from being an hps replacement.