With LED'S it's more about the spectrum than the par readings.LED lights do not have the coverage area of HPS and that is the main reason there not used in many commercial green houses.HPS lights are a great light for growing large crops but thanks to LED'S you can grow excellent weed without all the heat issues and money spent for cool tubes,ducting,blowers and etc.They both have there place and as indoor growers we should be thankfull for both.
I agree with you. 1000w Hps also has penetration on its side as well.
The 6" max fan will cool a 1000w air cooled hood or 2 600w open hood gavitas and exchange enough air in the room as well. Even led setups need air exchange.
For the sake of the OP.
i compared mars ll 1600w (800w) with the gavita 750 (up to 825w)
heres the skinny.
mars II 1600w (780w)
$650
http://topledgrowlight.kancart.com/item_detail/71-Mars-II-1600W-LED-grow-light-#!detail
Gavita 600/750 DE flex (400-825w)
$401.35
https://www.growitbest.com/gavita-pro-6750e-de-flex-400825-watt-120240-volt-p-4827.html
6" Max fan pro 420cfm 3speeds
$159.42
https://www.growitbest.com/canfan-max-fan-pro-series-6-in-420-cfm-p-4942.html
So including shipping you're paying about $50 less than a Mars ll 1600w. But you also get the best 6" fan on the market too.
.
These two lights are going to cost the same to run, power wise, but with no money left (after buying the led) for exhaust fan you have an incomplete setup.
I think both would give pretty equal results once you dial in the kits.
Am I in agreement that Every setup needs exhaust? why not choose the option where you get the best fan , and For free in this situation.
Now even consider you just get a 600w mag ballast and a Phillips lucolux bulb inside an inexpensive air cooled reflector( at the same site) you would have similar results but for a couple hundred cheaper and being several degrees cooler because of the a/c hood.
this example would be perfect for a 4x4 or 5x5 tent.