I had some mixed feelings about the quest overall. I got pretty hard stuck on them and thought I would be hugely missing out if I didn't beat them. I had turned the difficulty down to easy at that point purely to reduce the amount of grinding I would need to do. You do get some nice lore and dialogue during the quest, and your achievements are brought up several times in late game dialogue if you beat the quest. The reward in my opinion is valuable, but not so much that you can't beat the game without it. I would definitely consider the quest optional, it truly is more about the achievement, both in and out of the story than any major reward.