This carry rig is horrible for a couple of reasons.
1) It makes the carrier look like an idiot.
2) Small of the back carry is difficult under duress or in a clinch.
3) Small of the back carry is even more difficult when the gun you are carrying requires fine motor skill (turning off the safety switch) to activate.
4)The gun has a compensator, which wrecks your night vision and blows hot gas and soot in your face when firing from a retention position.