From Shotguns by Keith:

On a properly made gun there is a joy to the shooter, when he opens the piece and hears the soft punk of the ejectors kicking the empties clear of the gun. If you do not have ejectors, you are certain to get in a hot corner sooner or later while birds raise all around you and just when you should be dropping a couple more rounds in the gun you will be fumbling with those empty cases, trying to get them out of the gun the while you watch one beautiful opportunity after another fade away on fast wings.