The best loads currently are Federal's HST (amazing expansion ...up to .70 for 9mm, and it holds together very well even though it is not bonded), Federal's Tactical Bonded, Winchester's Ranger T (the most up to date evolution of the Black Talon), Winchester's Ranger Bonded (currently the FBI load, and what I use personally ...how I managed to get these in Kenya is another story ...), Speer Gold Dot (a lot of good OIS with the 124+P), and some all copper bullet by Barnes I cannot recall off head right now.
Anyway, the most important aspect is bullet placement. Even ball ammo will do the job if you do yours.
I agree about the Critical Duty. I had just bought into the Critical Defense when the Duty came out and had to switch my guns to Duty as soon as it was available.
I agree that aim is most important, but insist that the best equipment is called for as well. Doing your part is a lot easier to say than to do once others are shooting back at you. Good commercial/police rounds are far superior to FMJ in causing a more severe wound and thus a higher potential to neutralize a threat.