Sling suggestions for a service rifle.

Me as a private citizen have used a bunch of slings but the one I keep coming back to is a single point of adjustment sling. I'm able to strap it against the rifle and when I need the sling I pull it and adjust it.

The thing being I want to buy the same single point of adjustment sling as a present for a family member in law enforcement but they have a two point adjustment sling already with the slack elastic banned up.

So my question is for Leo is there some sort of advantage?