An unloaded gun is a very expensive club. I store almost all my guns loaded. I take the safety rule "treat every gun as if it were loaded" literally. If you see a gun in my house, you can bet it is loaded.
The Glock does not have a "second strike" capability. I used to prefer the ability to try a round again. It MAY go off the second time. I now feel if the round is bad, get rid of it (rack the slide) and go on with a second round (tap-rack). If it did not go bang because it hit on an empty chamber, snapping the trigger 100 times will not make it go bang. Tap-rack and get back in the fight.