Honestly to me it's nothing impressive. Anyone with a good background in Boxing, TKD, and Judo could come up with the same kind of system if they put in the time and effort.
What is impressive is the fact that they are competing full contact on concrete floors. (I know that it looks like hardwood, but I suspect, from my own personal experience, that it is vinyl flooring overtop of concrete. A lot of buildings in Korea are floored like this.) Most other KMA's that boast to have those kinds of skills generally don't spar full contact because they are th3 d34dly.
I really like what they're doing, even if it's been done before. I'd really like to see the flare they add to it. Kind of how Daido Juku still looks like karate, I want to see how this looks after a couple of years.
There will be people cashing in on Gongkwonyusul in the US.
The question will be how long they last.
Looks pretty good to me. I just hope that a decent school arrives in the NYC area before the whole thing becomes a rampant shitfest.