Finally completed Ys IX. Good game. Not as good as YS VIII. Shit port.
I believe 8 is the superior game so if you only played one, make sure it is that one. IX tries to do things that the engine clearly wasn't meant for. You get to run around a big city and you great a lot of new movement mechanics, but it all just doesn't come together as well as you'd hope. The city lacks color compared to the island of 8. The new mechanics don't really improve exploration and combat all that much and are clunky at times. With that said, the core gameplay is still fun. Battles are quick and flashy. The cast does grow on you and as a whole, might be better than 8s cast. I did feel a bit sad during the credits knowing that most of these characters will probably never be in another game. However, Dana was what really made 8 and IX doesn't have a comparable co-star.
Don't buy on Switch. It's an ugly on another system and Switch version really has no excuse running this bad. I hear the PS4 version runs bad as well that only the brute strength of the PS5 or PC really make the game run decently. So if you are going to play it, play it on those systems.
I am curious on where Falcom takes the series next. It seems like the 8 formula is here to stay for the time being. I hope Falcom can build a competent engine for the next game. I don't need it to look top of the class. But it's clear that this engine was built for games smaller in scope and they stretched it to its breaking point. A analogy I would make is that if Nintendo took the Ocarina of Time engine, tried the next game the size of Twilight Princess, while also adding in the climbing and gliding mechanics of Breath of the Wild. IX feels like it wants to be part of the open world craze but I think it shines best in the smaller (but still decently sized) areas outside of the city.