The Swiss mint makes nice coins also in terms of production quality. Could be due to the composition too (all denominations except the somewhat unpopular 5 ct/rp coin are Cu-Ni coins) but I have seen many Swiss pieces in excellent condition ... Christian
If i remember correctly it has a plating of stainless steel, Swiss coins are minted with a very high standard as well.
As for the first part, I don't think they are plated. The technical data (composition, diameter, etc.) of all circulation coins, from 5 rp/ct to 5 fr, are here (PDF). Agree with the second part. Christian