It's one of my favorites as far just playing goes, the combat feels incredibly smooth due to two main things
>a dash that allows you to cancel out of attacks at any moment, essentially allowing you to ignore recovery frames entirely. In other musous you can ignore part of the recovery frames with the dodge, but in this one the dash can be used even in the middle of an attack, it's insane
>most characters have aerial combos, allowing you to continue attacking even when they get sent away from the ground. Combined with the dash, you basically have no downtime at all when attacking
As much as I enjoy the combat here, a big part of the appeal of any licensed Musou is the license, so if you aren't that big of a One Piece fan a lot will be lost on you.