My opinion on the dollar coin is it will never circulate until vending machines accept them. The earlier dollar coins were only usable in the USPS vending machines and I believe in the D.C. subsway fare machines. Candy bars and occasionaly a soft drink is about all you can get for your debased dollar today.

By the way, for those of us over 65, "seignorage" is the response to a late social security check [g].