I agree completely with preacherman's criticisms. Here's a few more.
Overseas, a lot of guys had 3 point slings. Some made ranger slings, or just used the standard issue one. I spent a lot of time on my feet and in crowds, but didn't go for the three-pointer. I spent cheap and bought a carabiner, which I used to clip a regular sling to the shoulder of my tac vest. It's a dandy system for the soldier on a budget. The only thing I didn't like about the carabiner method was that all that weight ended up on one shoulder. At the end of the day, having all that weight on one side did nothing for my "anthropometrics" (pg. 2).
Really it was more of a discomfort, but the way these guys make it sound, it's easier on the body to have one point bearing all the weight than to spread it out as with a three point sling. Having used the carabiner method (a more or less static system like the one presented) and a three point sling (dynamic, spreading the weight out), I gotta say the three point sling is a lot more comfortable. I didn't start to laugh until I got to this part though.
From the ad:
Easily retrofitted to existing weapons such as the M4/M16 and M249 Squad Automatic Rifle.
How bout calling it a Squad Automatic Weapon, or SAW for short? Nitpicky I know, but consider their target market. If an M-16 with a 203 attached is any indication, I would NOT want to have a 249 hanging off my shoulder all day, as this would bungle up my anthropometrics beyond repair. By noon I'd be praying I had the padded shoulder sling that came with the weapon so I could at least shift positions now and then.
Also, how does it hold up to water, ice, diesel, sun, sand, impact, etc?
It's an innovative idea, something new, and who knows, something truly useful may come of it. But as is, no thanks. I'll stick with a Blackhawk 3-point or my Lowe's carabiner.
Edited to add: The M-16 stock is far from fragile. If you want something that breaks under pressure, look for Mike Tyson at a spelling bee.