The odds of you firing the gun in self defense are very small. The odds of your firing seven rounds in self-defense and needing a reload...I can't even begin to imagine what the odds of that are. Even if it happened, under that kind of stress, most of us would probably perceive an unresponsive trigger before we perceived a locked back slide.
Agree to all of the above. Just my opinion, but it falls into the same category of argument as whether to carry in config 1 or not; some swear based on battle drills that it doesn't take appreciably more time to rack the slide after you draw it. Me, I'd just rather not have to worry about that extra step, even though I'm very comfortable with the drill. My wife on the other hand, REALLY prefers the lock to the rear feature. Since she may carry/use it, I want to think of her as well (same reason I got rid of my car with a manual tranny after we married- she could learn, just didn't feel as comfortable).