Optimising monetary fungibility is a very different technical objective from implementing "end to end" anonymity.

If we look back at historical monetary media, like gold, there was no "end to end" anonymity in the sense that people wre trying to hide their transactions. But there was full fungibility (at least optionally) due to gold's low melting point.

A minted coin could be recognised from one transaction to the next but then if a pile of them were melted down and turned into bars instead, the coins were no longer recognisable.

So "hiding the transaction" is a distinct priority from "showing the transaction" but optimising monetary fungibility. In that sense, cryptonote tech is persuing the former and darkcoin tech is persuing the latter by supporting pre-emptive mixing - or 'melting' while the coins are in the wallet. In darkcoin, the coin supply is being continually anonymised because it gets done in your wallet, the previous wallet, the one before that and the one before that. There is less emphasis on any 1 transaction and more emphasis on keeping the coin supply as a whole anonymous and fungible.

Whatever the specific comparisons on the effectiveness of cryptography vs mixing, they are largely irrelevant because darkcoin's massive redundancy and iterative approach blows away any deficiency. It's also a more holistic approach which addresses monetary priorities rather than security ones.

For a prospective monetary medium, thats the right way around in my opinion.

of all time - I would go with David Gilmour - Pink Floyd