Just a small thought that occurred to me:

With MD CoW, LoA becomes protected.  In effect (to a degree), CoW replaces itself many times over if it rescues LoA.  This will allow you to outdraw a (4cc) opponent who doesn't run MD CoW.  Maybe then in that match-up, DoJ becomes irrelevant, especially if the Type 1 metagame turns into a war of attrition over strips, which reduces mana availability.

As for the established top tier of decks, Fish is another match-up in which I see DoJ as having any effect.  The question then becomes whether 4cc with Crucible instead of DoJ is at least as effective in handling Fish.