I finally finished it. It took me about 20 hours.
Overall, it was quite good. I think it accomplishes absolutely everything Ys 7 set out to do in a better way. In terms of gameplay and stuff, my complaints are fairly minor. I think the map design is done in such a way to deliberately make people like me uncomfortable/anxious, because there are so many branching paths that I'm really worried about missing stuff. Most of the time in the game was probably spent backtracking to make sure I'm not taking the "right" path that leads toward progressing the story.
As an Ys 4 game, though, I'm less positive about it. It takes many concepts from Dawn of Ys and Mask of the Sun and uses them kind of half-heartedly, to the point that the game kind of feels like it's just got an Ys 4 skin on top of it "just because." They've taken characters that we got to know years and years ago and made them completely different just to fit this new vision, which just didn't sit right with me. I think this game goes even further with that than Lufia DS did. It makes you think, "why did you even bother to relate this to Ys 4?" and that's not the feeling I wanted to have about the game. : For years, I dreamt of finally seeing Falcom's version of Ys 4, but I highly doubt that this was it.
Still, though, as I said, it's a good game, and perhaps if you go into it not thinking it's an Ys 4 remake or anything like that, it'll be easier to get past that. Or if you never played the other Ys 4 games at all.