I have found the Ohno copper great for the male end but it's a bit soft to provide a firm grip on the other end.
Also, I'm not sure that Ohno copper in itself creates a better termination. In fact very few AC terminations use copper at all, most are brass or bronze and there seems to be many satisfied users. There are probably fewer than 10 terminations that actually use copper. Same is true with AC outlets (even fewer copper IEC inlets, less than 5?).
The Furutech I mentioned uses copper for the male end and phosphor bronze on the other. Again my main issue with the Neotech is the mechanical design of the connection for the actual AC wires, adequate but could be better. The Furutech and Oyaide method is superior IMO.
As far as plating, for me a necessary evil to avoid oxidization although I don't like rhodium. I'm not sure about platinum and palladium either. A lot of these issues are probably system dependent so best not to make blanket statements. If you don't like plating, that's up to you.