I can see why people think this is the best or worst Dusk game. Its synthesis is much weaker than it was in Escha and Logy, with now there being a stronger focus on exploration. I only felt satisfied playing around with it towards the end, but it doesn't allow you as much freedom as it did before. They also dulled the difficulty too much and simplified the combat by removing the positional system. It was actually TOO easy.
However, everywhere else, I think it does a great job of merging the strengths of the past two games while having a story with stakes. It has the best atmosphere, having the adventure of Ayesha and the homey town feeling of E&L. The story ties all the loose themes and character arcs in a way that stays true to its slice-of-life approach while being more serious than it has ever been. The only complaint I have about the writing is the way the Shallies' relationship could have used more time to bond like Escha and Logy. But, it's not narrative-breaking and it has the best supporting cast to make up for this.
Overall, I think despite having a story with stakes and finality, it ended up being the least stressful experience in the trilogy. In many ways, it took a couple of steps back but landed gracefully.