Like I tried to point out, (poorly perhaps ) in my reply to an earlier post, what Overload says about Body armor is true, however, most of us here do not, and probably never will, wear it, so for us at any rate, that aspect becomes a moot issue .
That being said, the increased controlability of your long gun, and the fact that you do not have to change stance if/when transitioning to a hand gun means the square stance is still practical for "the rest of us".