In the original release of D2:ED Ba'al would drop unique class equipment (I got a hammer that I used for the rest of the game, though I had the fjords mostly cleared before I returned to Broken Valley). In DKS he only drops elder and epic class equipment.
I found the loot pretty good in the Gremory chest, though I did reload 10 or 12 times while I was doing something else, and got 2 epic pieces of jewellery; a good upgrade for my earrings and an ok one for by bracelet. That was at level 37; I reloaded saves at level 30 and 25 to try the chest then, and got pretty comparable results (at level 25 I had a couple pieces of level 28 equipment show up).
You can send any excess inventory items (gems, plants, maybe charms, etc) to the battle tower chest (the battle tower remains available in FoV, though the teleporter shrine will be disabled, so you can not leave to get back to the fjords, Broken Valley or outside on Sentinel Island).
Use the skill books that you have (and the Potion of Wisdom, if you didn't turn it in to Allen for one of his platform quests), or they will be lost when you enter FoV. The quest item inventory section gets cleared, and books, scrolls, keys, Vacca's Gem and junk items (mugs, plates, etc) are removed from your inventory.