What makes a Premium character premium, exactly?

I actually think you make a very good point OP! Aside from Duffman, I don't know about any other premium that has gotten more tasks or quests. It would be highly appreaciated, since they do cost money as you pointed out. Some kind of reward, easter egg, extra quests or something when EA adds on to the game, would be great! (And make the premiums more worthwhile).