Listening to different folks expound their opinions about the importance of "magazine capacity", or ammunition capacity differences between revolvers and semiauto pistols, is all well and good. Folks, especially ardent enthusiasts, need their hobbies, after all.
However, once we take the "discussion" down-range and require people to
perform, especially under increasingly demanding conditions for which they haven't been able to "prepare themselves" by first observing a course-of-fire being performed by someone else, and mentally "walking through it", so they know what to expect ... it's accurate, controlled holes on the intended threat targets that matter.
If higher capacity just means having to identify more misses, it sort of misses the point.
I'm certainly not saying that someone wanting to choose to carry an issued 17+1 9mm is "wrong" for choosing it over a 10+1 .45ACP, or even a 6-8rd revolver.
It's only when someone thinks they ought to offset or compensate for their lower skills by substituting the carrying of more ammunition for working to develop those known lower skills, that I start to wonder about their priorities.
I finished my regular career by carrying a 7+1 4513TSW .45ACP as an issued weapon for my plainclothes assignment. Some time after I'd been serving as a reserve, post-retirement, I traded that 7+1 .45 in for a 8+1 3913TSW 9mm. Why? I liked that single stack 9 (and already owned a 3913 and CS9), and found it nicely balanced, fast-handling and very accurate. (I later bought it when we were allowed to choose one former issued duty weapon for private purchase.)
I finished my reserve time by carrying an issued M&P 40 (15+1), because so many people wanted to choose either the M&P 45's/9's in the inventory, so when it came time for me to be issued one of the new guns, I told the guy responsible for issuing them to just give me whatever wasn't in high demand. It was just a duty weapon, after all. I could use all of them, when it came down to it (and I even owned a full-size M&P 45 of my own, and a M&P 40c). Let other guys and gals choose whatever tickled their fancy.