Well to be honest, i am going from shooting a 9mm for 3 to 4 yrs now. So to me, saying "UPGRADE", I mean penetration. I just want something with more PUNCH. Maybe upgrade wasn't the best wording for it, however that is the word i use going from a smaller caliber to a larger caliber.
Well you really wouldn't want to go to that fat and slow .45 caliber. What you need is a snappy .40 for ultimate penetration. Numbers don't lie. https://www.luckygunner.com/labs/self-defense-ammo-ballistic-tests/#results