I heavily farmed and stockpiled the old armor, but when EoF dropped it soon became obvious that there was no need to keep anything except our old exotic armor. Everything else is power-crept by the higher number of stats on new armor. That should free up a lot of vault space for you. Get rid of all old legendary and artifice armor. Only keep your old exotic armor if it has high stat rolls of mid 60s or better. I was able to make the new armor look exactly like the old armor by using ornaments on the appearance screen for each piece. Another useful tool for clearing vault space is the shooting range. If you are keeping multiple rolls of the same weapon or even different weapons with the same perks that perform a similar function, go to the shooting range and try them out on a variety of enemies. Figure out which ones are the best for a given purpose and delete the rest. You can test them on anything from crowds of the lowest level ads, to shielded mini bosses, champions, and even big bosses. I was surprised to find out that many perks I never use actually performed better than my favorite combos. I was able to get rid of a lot of duplicates with minor perk variations that I had been saving to test one day.