There is however an energy difference.
No doubt! That's why I said that 9mm is much better and logical choice, since the firearm factor is the same but the energy delivery is more than doubled! While we can argue till we are blue what's a better way to deliver 500-600ft/lb (9mm vs 45), 380 is just not in the same class. If recoil was that big of an issue, I'd go with 22WMR over 380 hands down.