Four weeks or thirteen weeks? Look as a user sometimes I do need money urgently and powering down instantly could be a great option (Ok right now price is so low powering down is really not a good idea, not with the SP I have). But instant has its drawbacks the main one security, are we willing to forfeit security for the chance to withdraw our funds as soon as we want them? But if we do need it urgently and its not instant I don't see the difference between thirteen weeks or four weeks, I still wouldn't get the money on time. So weighing these in I think personally I would vote to remain with the thirteen week system, it is less risky.