Finished the DLC and the (nerfed) final boss fight on ng+.
On the plus side, there was so much amazing content in the DLC: a beautifully crafted world, several memorable and challenging bosses, a well-(un)balanced leveling system for players at all levels, and pretty awesome selection of weapons and spells.
However, the final content was probably my least enjoyable FromSoft experience, and the reward for dipping that much time to learn the boss fight was shockingly disappointing. Not sure if I will replay the DLC on subsequent playthroughs, and if I do, I'll probably skip the final content.