Generally speaking, the two primary uses for a sling is to carry the gun, and the other is to serve as an aid during off hand shooting. The first is almost a no brainer and can be done ever how you want, and with what ever style of sling you want. The second however, requires training/understanding/mastering of the what's/why's/how's which are involved in order to obtain the desired results, which in turn is going to dictate "which style" of sling you'll need...which just in passing, probably ain't what you're seeing those "young LEO's" wearing around their neck.
On the other hand, if all you're wanting is some way to keep the gun on your person while awaiting your turn to disconnect it and commence shooting, and/or if all you are doing is shooting off of a bench, it don't much matter what sling you use in the mean time...
I mean really, as a practical matter...if it's not going to be used (or attached) while shooting, how much difference can one sling possibly make over another?...just go with whatever suits you.
DGW