To comment on "not needing duplicates" statement, having duplicates can actually create space and efficient. Not to insult anyone's intelligence but some have minds that don't over evaluate things, but for every item you have that you use on all your characters, requires a slot free for you to drop off and move to the designated character of choice. So for example, if one finds himself using "Black Hammer" and "Gjallarhorn" (which most I assume do) then depending on how full his bags are, he could get away with that one slot but if he had maxed out in either his secondary or heavy slots, then he'd need two vault slots just to transfer those items. Obviously, this is probably a select portion of the population, I'm included unfortunately because I like keeping raid weapons as they have their own specific needs at times, but having three Gjallarhorns and Black Hammers makes it easy and knowing I have a few extra slots that can be used for storing and not transactions between characters.