All handguns are relatively poor 'stoppers' regardless of caliber or bullet used. Shot placement and sufficient penetration are paramount, all else is secondary.
Barring a hit to the CNS, the only way to stop a determined and aggressive BG is shutting down the brain from oxygen deprivation via bleedout. A solid hit to the heart can leave 10+ seconds worth of oxygen in the brain, plenty of time for the BG to plant daisies in your hair.
With that being said, unless the bullet used can alter the outcome of the encounter by incapacitating the BG via blood loss (unlikely, remember the 10+ seconds after a heart hit) before he can inflict serious/lethal damage, it really doesn't matter if bullet 'X' causes the BG to expire in the ambulance instead of the ER. I doubt a determined & aggressive BG could tell the difference if hit with any of the quality loads currently available.
Personally, I like both the 135gr Critical Duty and 124gr HST in my 9mm's w/the edge going to the CD for greater assured penetration at the cost of some expansion.
JMHO...
Tomac