I saw a film - called Daredevil. In the film Electra picked up a Glock and shot at Daredevil, and after she ran out of ammo she kept pulling the trigger and the Glock went CLICKA CLICKA CLICK...
Just to add to that count, if you watch NCIS they chamber a round almost every time they pull their gun out of their desk ("grab your gear!"). You never see them eject the round, eject the mag, put the round back in the mag, put the mag back in the gun and put the gun back in the desk for next time.
I used to keep my weapon in condition 3, but eventually changed to condition 1. I think it's fine, just trading one risk (needing your gun to fire NOW without assistance) for another (having your gun fire NOW when you'd prefer it not or having it fire the second someone takes it away from you). I think it's just what risk you're comfortable taking (for instance I don't train for the FBI shootout).