I think most people on this forum prefer heavy for caliber loads and prefer penetration over expansion. I believe all of us know that regardless of ammo, if you don't hit anything vital, you are not going to stop your attacker. So a lot of folks will test their carry ammo to make sure they are consistently accurate with what they choose. That's how I am anyway. Since I carry an S&W Shield, the 9mm Ammo Quest videos are directly applicable. So I have tried pretty much all the ammo that has passed the quest. I find that 124gr standard pressure HST is something I know I can find and buy, and I can shoot that reasonably consistently accurate, that's what I carry in my Shield. I also can shoot the 147gr HST pretty well, too, but man, they are hard to find! I like the 147gr HST better, but I can't find them reliably.