Just read the article. Not sure what is gained really. A 10.5" or 11.5" 5.56mm would be my choice and give you about the same weight. Yes it will be longer but you can also reach out and touch some one. Use a G18 with a stock for a tiny 9mm. The ability to share parts, magazines and ammo when Murphy shows up would keep me from going this route. It is what has kept me from buying a 6.8.