A lot of people ask about rifle sling usage, here's my take. I run a very simple set up. It doesn't quick adjust, it isn't padded, hell it attaches to the rifle with leather loops!
I run the sling at the rear of the rifle receiver then at the front mount on the rifle. It is slung only over my neck, which allows some usage like a single point, but with more control. You can transition shoulders easily, go prone, muzzle up, transition to pistol, move, etc very easily. It is as stable as a standard two point when slung? No. Is it as easy to transition shoulders as a regular single point? No. Jack of all trades, master of none. All options have trade offs, this option fits the bill best for me.
He's a video from last weekend showing a lot of the positions discussed above on the VTAC barricades discussed in Kyles book. Please excuse me forgetting my canted-rifle holdover
twice and my terrible pistol work at station two.