... SSK did not invent taking a 223 or 221 Fireball case and making it 30 cal. The first documented use I have seen was 1969 for the Colt IMP pistol. ...
Maybe, step back for a second, take a larger view, and try to realize how completely you have missed the point.
The point: Use the 223 Remington case or a variant of that case with a 30 caliber bullet in an AR-15 with a suppressor at subsonic velocities.
Who did that first?
The counter point: We all know Christopher Columbus did not discover the Americas first, however, after he "discovered" it, they stayed discovered. Or a different way of saying that is: We all know AAC didn't have a shread of originality when they made the 300 Blackout, but the idea is good, and the partnership with Remington made this great idea of JD Jones comercially viable, and this is good for all of us.
That said, people shitting up threads isn't nearly as good for all of us.
And just for clarification, re-read Absintheur's Great post in this thread. Actual experience with one of these cartridges for 25 years or so. If Absintheur posts his dislike of the 300 BO in every thread based on his 25 years of experience, how is that any different than Dave posting how bad the M9 is? Or all of ZS posting in every birdshot thread how birdshot if for birds? Or how much love ZS gives the Mini-14?
Either way, staying on topic for me now: 1) The chamber of the Blackout can shoot both rounds, 2) the Blackout has more industry support, and 3) the rounds are so very close to the exact same thing that there is little to no balistic difference. With 3 being a wash, points 1 and 2 favor the Blackout.