Thank you for this first answer. My experience with gold kits is limited (and not good) as I use only Titanium gold, Black Ti, Platinum, Chrome and satin nickel kits, all coatings and platings that hold up very good to excellent. Someone had asked me for something different in plating colors. Lately, I have seen quite a number of pens in these copper platings, and liked them. I think that might go very well with certain woods or plastics. My experience with copper is that it will tarnish easily and must be somehow protected if one will keep the shine.
I also have absolutely no experience with epoxy coated platings, the suppliers of my kits do not use them.
So, if the copper plating users could give us some more input here and let us know how the Cu is holding up.