Ive been using the Savvy Sniper sling since this thread put me onto it.
I have had two problems with the sling. First, the HK hook failed during a movement when I wasn't holding the rifle in my hands. The rifle took a nose dive in the dirt. Not a happy camper. I used a multitool to straighten the bent part of the hook out, it works but is always threatening to pop off again. I think this is a fault of the hook rather than the sling itself.
In hindsight I would go with the QD mount if I could do it over again.
Second, the adjustment part of the sling, it is a great design with nothing dangling down. However, it doesn't have enough adjustment, I cannot tighten my rifle to my chest. It's always bouncing off me and getting in the way, a constant frustration.
Just my .02c