Welcome aboard!Without going into a long technical explanation, none of them will fire unless the trigger is pressed.it along with the glock have internal safeties, (can someone explain how they work)That kills the Glock, the M&P, and 99.99% of XDs. But of course an external safety is redudant if you simply commit yourself to the Cardinal Rule: Keep your booger hook off the bang switch until you're ready to fire. Train accordingly.but for my peace of mind i think i need an external safety.No, but I think with proper training you will be. Good training inspires confidence.you think with time and confidence i would be ok with no manual safety?BZZZZZZZZZZT! Wrong answer! You do not, cannot, must not rely on the pistol to safeguard your children. Only you can do that by acting responsibly with your weapons 100% of the time. Not 99%. Not 99.9%. Not 99.99%. 100% - or nothing.i have 2 little girls and heaven forbid if i ever accedently left it within reach i want to be sure they couldn't just pull the trigger!
If you cannot commit to being aware of the gun's location and condition at all times, do not own a gun. With small children around, the gun must always be safely stored under lock and key, or in your immediate physical control. It must not ever be anywhere else.I know extra safeties appeal to newer shooters, but grip safeties do nothing to enhance safety on a modern pistol - unless you do something really dumb like carry it with a loaded chamber stuffed in your pants without a holster. Guns don't just discharge on their own. Negligent discharges happen with the pistol in hand, when the grip safety will be depressed and deactivated anyway. All modern guns are safe when dropped, so the grip safety buys you nothing there.i really like the xd9's backstrap safety, i think its a nice feature.
As you note, the Ruger remains unproven. The other guns are proven to greater and lesser degrees - the Glock the most, the M&P the least, and the XD in the middle. Of these guns, Glocks are most popular in competition, followed by the XD.
The Glock has the advantages of low bore axis and shorter trigger reset compared to the others, but these are things that go unnoticed by new shooters. The XD or the M&P may fit your hand better. You may prefer their trigger actions, as well.
Best idea is to try to shoot them all. Handling them in a gun shop is okay too, but it gives you very little idea about how they behave when actually fired. Good luck with whatever you choose!