I added the same sling to a rifle of mine for about five minutes. I went with a different mounting point and a different "stub" though:
For me, the advantage of the HK style clip is that you can have the quick detach feature, but when you are not using the sling at all, you can easily remove the entire stub so that it doesn't get in the way.
I shot one match with the setup pictured. My only problem with it is that the MI mount has a piece on the inside that is designed to fit into a gap opening in the endplate that does not exist on my particular endplate, creating a gap. So, I removed it. One day I will get around to ordering an LMT single point mount that will work perfectly with my endplate, and it will be perfect.
The single point seems to be good for emergency weapon retention (I would assume) and shooting from either hand around cover, but bad for controlling the weapon while transitioning to a pistol or otherwise using your hands for something else. I don't have a huge amount of experience with it though.