The math is easy, you’d absolutely need 8 to get to 1000 watts. But even pounding on the qb’s they’re 10% more efficient. Running them 115 Watts or so per board I think it’s almost 15% more efficient. So same amount of light for 850 Watts.
Here’s the difference in les,
I believe the difference in coverage from 12 cobs to 6 qb’s will fall into favor of the qb’s. And when you consider lower intensity level per square inch, you could definitely run the boards closer without seeing those light damage issues. Which isn’t really a benefit, just juggling act between height and par levels. But it would certainly make up for the difference in that other 80-100 Watts. Having the “Watts” with the cobs isn’t really a big advantage when you have to either raise them or dim them correct?
That being said, I’m in no way suggesting you should get them lol. I think you’re pretty solid. The qb’s are just a more expensive, more efficient option.