I see, yet I'm still confused. I've read in another thread that a subclass bonus is tied to it's parent class source (I'm I wrong on this?), meaning that, say, wizard elemental spells get no bonus from the fury subclass, nor do the druid spells receive the evoker subclass bonus. In short, synergy is.. well, not very synergistic as I understand it.
Is the added flexibility of a dual casting list really worth it?