A regular three-point sling can present a choking hazard when transitioning to the weak-side shoulder.
Another consideration with the three-point sling is that the multiple straps can get hung up on SWAT gear or load-bearing harnesses. In addition, for left-handed shooters, the strap closest to the gun can interfere with an AR-15's ejection port.
Specter Gear, once called CQB Solutions, has made some of the most dramatic improvements in three-point sling design. The first basic improvement is an emergency release buckle (ERB) on their CQB Sling, which untangles the shooter from the main sling loop. The next improvement is in the Cross-Shoulder Transition (CST) Sling. The CST has a slider which allows the shooter to adjust the body loop position on the fly, which allows him to shoot from his weak-side
Two- and three-point slings may be connected to the front of the rifle either with a simple loop, or a quick-detach (QD) swivel. Here the Knights Armament QD sling swivel is used.
The SPEC-OPS Brand MAMBA sling is very similar to the Specter Gear CQB Sling, but distinguishes itself with a bungee portion of the body loop at the rear of the sling. The addition of the bungee material is unconventional, but sometimes just a little more mobility is required when trying to clear gear or transition, and the bungee can provide it. Finally, the Blackhawk Industries Swift Sling follows the same basic three-point pattern, but has a buckle for cross-shoulder transitions. Once this buckle is released, it requires two hands to reset and is somewhat awkward.
Most of these slings can be fitted to carbine, rifle, shotgun, or SMG with adapters available from the manufacturer. Single-point sling designs generally need a receiver loop. Two- and three-point slings can be attached to a the M16A2's fore-end and stock, or they can be connected using the quick-detach sling swivels pictured in this article.