I'll start by saying I know this is an old Thread but reading through it I only saw this Post that mentioned the Nickel Plated Cases moving easier. The easier movement is what Plating is All about. The Nickel acts as a lubricant but unlike oil type lubricants it is designed to stay on the case and will also protect it from the acids in leather - which Was mentioned. Nickel Plated Cases are simply better.In my experience, the nickel plated cases that I have run through a sizing die (IIRC) were easier to run through the die because of the plating - or so it seemed to me.