What is your goal for the length of time it will take an endgame caster-spec'ed warlock to beat down of an EE bag-of-hitpoints with eldritch blasts? At this point, we've seen what paladins and barbarians can do to that hobgoblin and how. And also how relatively pitiful wizards, say, are at performing this task. Where would you like to see warlocks in this respect?