The S9 is the model I'm looking to possibly buy next. It uses Lumen COBs. Again, there are Vero29 Gen7 models as well, if you want to go with a "tried and true" COB. 270w wall draw, they say it is equivalent to 810w hps. I trust ShenZhen after owning a couple of their lights now.
Is running $500 on Amazon, under $300 factory direct on Alibaba. Don't know about taxes/tariffs/shipping, you'll have to contact them to find out. Don't know it's effectiveness because it's a new fixture.
Here are examples of the Vero29 units and they have CXB3590s too.
I don't know how they stand up against the Quantum Boards.