You know that teal, 2-slot cloak you get from (I think) completing the U23 Black Book chapters? That one that’s level 115 and therefore can’t accept any new essences?
You can now trade for the level 120 equivalent at the barter vendor in Skarhald. It costs 1 Mark of the Longbeard. I’m assuming you can’t trade for it w/o having finished the story, but IDK.
Stats are only slightly higher. The key is that you can slot new essences in it.