Yes, unless I need to travel really light. As said before, the extra mag is for primary mag failures because, to me, the likelihood of a prolonged shootout seems remote. Of course, I would really hate my last sight on Earth to be that of my slide locked back and my last thought to be knowing that the bad guy's isn't.
I'm not sure I would carry a speed loader if I carried a revolver. But speed strips are a maybe.
Now my problem is with a cell phone, light (at night), extra mag, knife, gun, and OC, I'm really starting to feel like I need Batman's utility belt. Picking which goes on the belt and which goes in the pockets is a work in progress. It's probably why I opt for my murse or fanny pack more often than not when I have to go heavy.
That said. The extra mag is usually the last one voted off the island when I have to trim down.