After 20 years of active duty military experience and nearly 30 years involved with professional civilian handgun training I have observed that:
1) Handguns are at best of tertiary interest to the Army.
2) The criteria used to select a handgun for the military includes several factors of very limited value to the civilian self-defense practitioner and fails to address several other factors which are critical to that user.
3) Only a VERY small minority of all military members EVER fire a handgun.
4) The training provided to the majority of military members who do fire a handgun is extremely rudimentary. (InSights General Defensive Handgun course is far more in depth and the material in our Intermediate Defensive Handgun course is not found in the military training system other than a few special operations schools.)
Based on the above observations it is my opinion that:
What handgun the Army has chosen for standard issue should have exactly zero impact on what handgun a civilian should consider for self defense use.
March 3, 2017
Via the InSights Training Center email list regarding the Sig P320
[I have nothing to add.—Joe]