The chest is only 10" deep on the typical individual and most JHPs have the ability of over-penetrate. However, most shot fired under duress will not be under the most ideal conditions with frontal shots not a given, and even an arm acting as a barrier can prevent a light bullet from reaching the vitals.
Personally, I've decided the G-A 115 +P+ GoldDot is the ultimate defensive round for me. Super accurate, consistant and packs tremendous punch for a 9mm. My K9 loves it and that's good enough as far as I'm concerned. I not one to constantly chase the current fad.
Having the ability to push a uniformly expanded 9mm roughly the diameter of a nickel with 100% retained weight 10-12" into an assailant is good enough for me.
I think I'll stick with this round until I either switch calibers or pulse laser pistols hit the market.