Trumpy,
You are right to worry about half-out plugs. As far as I can remember, these were the sorts of things always used as examples of how home fires start.
If a plug is just barely making contact with the receptacle, and there is a sizeable load on it, the plug prongs can get red-hot. As you might guess, this sort of heat will cause the wire insulation in the cord, the receptacle, and the wires in the box to degrade, and eventually fail.
Just the sort of thing the AFCI was originally claimed to protect us from.....but that's another story.
One of the big differences between a quality device, and a residential one, is the amount of tension in the springs that hold the plug in. All devices will weaken eventually- but if a receptacle is used frequently, or is expected to hold against the weight of a substantial cord, getting a better device to start with makes sense.
