I have the Ref 2 Silver, and think it's great. I believe they changed it to Ref 2 "copper" a year or two after I bought the silver.. I do not know the difference in sound. If I could do it over I'd have gone straight to the Ruby or I'm told the Cardas Heart which is a Ruby with a different wood body. Although the Cardas Heart is supposed to be better, you cannot get a trade-in to purchase like you can with the Benz line. Sorry I cannot be of more help with the Ref. models.