9 x 23...powerful, perfect in a 1911 platform, a straight-wall case, solving the problem of he slightly tapered .38 Super case, one of those rounds like the .38 Special and the .44 Special, where every relad I tried shot well, lots of el cheapo 9mm Largo for practice..and a SPECTACULAR FAILURE! LOL!
I say again...this is a "fashion" question...carry the caliber you like and adjust your tactics accordingly. Heck, if you whip out that little N.A.A., have some sort of plan to offset it's (numerous) shortcomings! Carry 2...or 3...or get the .22 Magnum version! LOL!
I try very hard to avoid the whole "best" discussion, but It's important to explain my own choices. That is, of course, when I have logical reasons!
Michael B