I have and have used a bunch of slings, one-point, two-point, three-point, and loop slings to stabilize the rifle for target shooting. Any two- or three-point sling can be used as a "hasty" sling to stabilize the rifle but slings that can be used as loop slings are preferable, especially for sitting and prone shooting. For three-position shooting I prefer the leather 1907 type loop sling although the inexpensive USGI web sling works pretty well. Magpul also sells a relatively inexpensive two-point sling that can be set up to use as a loop sling or Rhodesian-type sling - the RLS sling. It works pretty well but the distance from the loop to the fore-end anchor point cannot be adjusted quickly like the 1907 or the USGI web sling.
I hate one-point slings. I suppose they are good in three-gun competitions and the like in which it is necessary to drop the rifle and quickly transition to a pistol. But they suck for carrying the rifle any distance and they are useless for stabilizing the rifle for precision shooting. If I really felt the need to be able to quickly transition the rifle from strong to weak side shoulder, I would go with one of the two-point "tactical" slings with a quick adjust feature for length, such as the Blue Force Vickers.
I actually like the much-maligned three point sling. If I were the type to be running around wearing a plate carrier with four double mag pouches hanging from my chest (which I am not) I would probably avoid the three point sling because people way more experienced than I am say that it is prone to snag on gear and can interfere with rapid access to the controls on the left side of the rifle and rapid magazine changes. But the three-point sling makes for very comfortable and stable carry in the outdoors or at a range and works better to stabilize the rifle when shooting than a simple two-point hasty sling does.