Those who have served and carried an M9 often pick up the weapon outside of the service. Like many of my brethren, I am one of those who did perhaps for the nostalgia or familiarity with the weapon. Frankly, I like the M9, slide mounted safety be danged.
But, one is not limited to keeping their M9 factory-new. With the platform being over 25 years old, various upgrades exist that make the weapon better for self-defense. Even recently, Wilson Combat has released new products and full special edition of the handgun. Those primary upgrades being a different trigger and hammer springs.
While Beretta (sadly) does not make the 92″D” (double action only) version any more, its legacy lives on in the form of the “D” hammer spring. The spring (typically rated around 18 pounds) combined with a new trigger spring, can go a long way to reducing the trigger pull of the M9. Double action drops from above 10 lbs to around 8 lbs, and the single action is noticeably lighter typically around 4 lbs. The Yankee Marshall shows the difference in a factory gun.
Combatting trigger spring breakage is Wolff Gunsprings, with their Wolff Trigger Conversion Unit, which changes the trigger spring into a coiled unit. It has a more stable stacking ratio, reducing the total pull, especially on the double-action pull.
For those wanting to get a bit more advanced, Wilson Combat has released a new trigger bar as part of their Ultimate Action Tune Kit. The bar reduce over-travel through the use of a boss on the bar. It requires minor gunsmithing to set the boss protrusion, but those with some time and a file will find it easy. While I have not tried one personally, one is on the way to see what can be done!
Bottom line, the Beretta 92 series does not need to stay stock. Many improvements have been released in the last decades and even the last few years to keep the platform going strong.