BTC though: Unstable rates...
USD has unstable rates. Yesterday 1 $ was 1.15 mBTC, today it is 1.05 mBTC. Can't use a volatile currency like that.
(it's all a matter of perspective)
I like the sentiment of this. My first reaction was 'yeah but that's because of the movement in Bitcoin, not in the USD', but it al amounts to the same thing. THe USD could easily be valued by its worth in Bitcoin. Good point.