I had a two-point bungee sling on one of my ARs. I'll never use it again.
The sling doesn't secure the rifle well enough; it can't keep the rifle close and tight to my body when I want it to. When the sling is loosened enough to allow me to shoot, then there is too much play in the bungee. The worst part of all is when the rifle gets hung-up on something. The bungee is stretched, then released, usually sending the buttstock at my chin.