It was pointed out to me at that time that I must not approve of a shoulder rig either as you have the weapon pointed to your arm at one point. (I don't wear shoulder rigs, but the Dirty Harry style would resolve that issue).
Also, the appendix carry has the same disadvantage, but I like the appendix carry.
So I guess it all boils down to training. Train yourself never to put your finger inside the trigger guard until you are on-aim and you should be OK.
Also, the SOB carry requires the longest of Tee-Shirt tails or it will reveal when sitting. That is not nearly the case with other positions on the body.