Keep whatever, but if you should seriously check out the in game vault sorting. It’s actually super useful/intuitive. Select armor, then sort by a single set bonus, and then easily compare which pieces you’ve got side by side. You may have some tier 3s and 4s that are just taking up space. Or even exact stat duplicates. You can even search for weapons of which you have duplicates. It’s one of my favorite additions to the game. (And you can swap pages super quickly on console.) If you’re playing all three characters, I guess I could see hitting max items, but are you ever gonna use that stuff? I’ve kept a bunch of weapons from many seasons ago, but I use them in crucible all the time. Keep what you keep though. Good luck. You ain’t getting any more space lol