People complain about the show being uniform??? Get out, that should be the whole purpose. I hate it when the characters look different episode by episode, it's really noticeable.
For example, back during Enies Lobby pretty much to Fishman island, there was an animation supervisor, by the name Naoki Tate, who had a visual style very similiar to that found in movie 6 and movie 9(that animation supervisor was literally the animation director for movie 9, they controlled how that movie looked). Outside of having a unique style, their episodes also tended to be highly animated, and had some of the coolest scenes in the series animation wise(for example, Luffy punching the celestial dragon was a Naoki Tate episode). Some people prefer that softer sort of approach to characters and linework, which is sort of missing from the show currently outside of a few big animators showing up to do small though nice scenes.
This is some of the production materials Naoki Tate did for movie 9. The designs are very stylistically distinct from Oda, instead focusing on shapes that accentuate natural weight and posture. It was certainly a unique take on the series.