Originally Posted by danf_fl
The magazine is THE weakest part of any semi-auto pistol.
This is the first thought that crossed my mind, and the most critical point favoring extra mags.
I usually carry one extra mag because my primary carry guns are quite limited in capacity. I typically carry either a 5+1 XDs or an 8+1 Shield.
When I carry a higher capacity XDm45, I usually don't carry a spare. Not just because of the capacity in the gun, but also the weight and bulk that would accompany that extra higher capacity mag. It's a personal decision. In a G19 I would say there's plenty of good reason to carry an extra mag. But I'd also admit that I probably would choose not to. I hate carrying extra weight. But I absolutely would
keep a couple extra loaded mags in my vehicle (or desk, briefcase, purse...or whatever suits your daily routine) if only carrying one.