"Police 870s have heavier springs in their action. While those actions may be smooth, they also require more force to cycle the action."
Not exactly according to the work I have done on them. The heavier sear spring makes for a very heavy trigger pull which, by nature, would prevent accidental discharge to some degree.
The heavier carrier dog spring operates the shell lifter in a more aggressive fashion.
Your article is about the differences between the Express model and the Police marked model. Most of the older Police trade ins I have acquired are Wingmasters. On more than one of them, the slide will fall to the receiver when the slide release is engaged and the shotgun is held in a vertical position. They are that slick.