I always have mine ready to rock and roll so it really doesn't apply to me. As for the average person, it really doesn't matter if the firing pin is released or under tension. You are going to have to put the firing pin under tension, when you load it anyway. By the way, Glocks don't have hammers, in the traditional sense.
I understand "firing pin on empty chamber/cylinder" on older weapons, but not on newer ones or LE/HD ones (Army MPS). Are you going to be able to tell the bad guy "Stop, wait a sec while I chamber a round, so I can shoot you." Then again, MP's have to put leashes on their guns so they don't lose them.