The Yuan is not a freely convertible currency, so not really an option here. The Euro isn't terrible, but it has structural issues in that member states all must take out debt in what is for monetary policy purposes a foreign currency. This generated a debt crisis 10 years ago, which has been papered over, but the structural issues remain unresolved. Also, the Euro has been around now for 25 years. That's not long enough to convince anyone of long term stability.