I never understood the aversion to the magazine safety. The odds of you firing a weapon in self defense are astronomical (unless you're Jack Bauer or something). If you DO fire a gun in SD, you're not gonna be counting shots. You're gonna pull the trigger until the gun is empty, and you may not even realize the gun IS empty. So you're not gonna be reloading a still loaded gun in the middle of a shootout. If you DO attempt this, it takes MAYBE 2 seconds to drop a partially full mag and seat a new one. The odds of you needing that one round in those two seconds is even more astronomical than if you get into a shooting at all (and this is assuming that you will have the presense of mind to drop a still loaded mag during a shootout). And even if you do, pistol shots aren't one shot, instant stoppers (unless you hit the brain. Good luck with that). So even if you get that one shot off, now you have an empty gun that still needs a reload, except now the slide is not locked back, so it will take 2 hands to load and rack the slide, all while someone is still coming at you.

On the other hand, the odds are MUCH higher that mag disconnect can save you. In the struggle for a gun, you're probably gonna lose (and please don't chime in with the "my tactical awareness is always at 100%, and if you let someone get that close to you, you need to work on tactics" comment. Nobody is that tactically aware all the time. Try getting the kids into the mini-van without them killing each other over a DS game.) Most robberies are in your face, push up close. Dropping the mag makes the gun inert if you feel you are about to lose it. I personally know 2 cops who are here today because of the mag disconnect. That's why S&W made the safety, since cops were their biggest clients for the 3rd gen guns. Not to mention that if you store the mag outside of the gun, the gun is inert. Nice plus if you have kids around, or a wife who really doesn't want to learn how to shoot and won't touch the things. Sure, I keep them locked up, but one extra layer of safety is OK in my book.

Do a search. Tell me how many people were shot because the couldn't reload their gun during a shootout when they had one round in the chamber, vs the amount saved by the disconnect.

Only downside to them is if you are going to use the gun in competion. IDPA rules are to drop the mag, rack the slide several times, and then pull the trigger before holstering. Mag disconnect prevents this.