Mr. Naro, you make a good point which is well taken.
One one side of the equation one wants to maximize one's ability to get the gun on target quickly, send rounds downrange, efficiently reload, etc. This might be accomplished with a Glock 17 and 3x 17-round mags on my belt. But there is no way in Hades that I'm going to do that. The other side of the equation tries to integrate these elements in a practical way that allows me to carry on a daily basis in a realistic and comfortable manner that fits in with my clothing, lifestyle, etc. This draws me to a small 9mm in the pocket, etc. I'm constantly trying to balance these considerations in my full EDC package, which includes not only the gun but an MT, knife, light, phone, etc. Maximum utility in the smallest package that works.
But yeah, I imagine needing a gun right now and a mag right now too. My current carry (pocket carry) is not optimal for deployment speed, but it does allow me to keep my hand on the gun and to have the element of surprise. It also allows me to live my life in a normal way without a 1911 bumping into the door frame or kitchen table 10x a day.
I'm rambling.
Everything we do is a compromise. I just don't see myself carrying a spare mag on my belt, and honestly I rarely carry a spare mag at all. But I have been carrying a loose spare mag recently when I wear 5.11 Tac-lite Pro pants with plenty of spare pockets. Maybe I should carry my Ruger LCP as a "New York reload". Its barely heavier than a loaded Kahr PM9 mag.
But thanks, I will cogitate on what you said. I think I am currently at the point where I would rather have a spare mag that takes 2 hands to deploy, than no spare mag at all. Rock on.