I've been researching defensive ammo for 9mm for a few days now and I think I've settled on Gold Dot 124 +P's for my Glock 34. I may also try out some standard pressure 147gr HST's. The +P HST's don't get as much penetration for a tad more expansion. I prefer the most penetration I can get in a given load.
I am just happy there's so much great technology out there in the bullet world to give us all of these choices!