I've finished Enies Lobby. So far, I like the game's combat system, but the overworld traversal is remarkably slow. Despite the environments looking very good, it also feels like you have less freedom to explore compared to previous One Piece games.
One weird thing I noticed is how the game seems fixated on explaining or justifying the different mechanics that you'd usually just overlook as game limitations.
Locations not being where they are in canon? It's because memory is fuzzy.
Enemies being stronger than they were? It's because memory is fuzzy.
The Strawhats can't use their later movesets? It's because their memory was stolen.
Nami's wearing a bikini in Alabasta? It's because Usopp prepared super sunscreen.
We have to go through a whole quest to justify being able to quick travel.
There are a lot of these little things and it kinda takes me out of the game.
I'll continue playing it still. I find some parts of the game charming, and it does look visually stunning. The NPCs look like generic One Piece background characters, which I think is nice (as opposed to generic RPG NPC), and the creature designs are a great throwback to Strong World.
In the end, Unlimited Cruise is still the best One Piece game I've played. I hope future One Piece games can lean more towards that direction but it doesn't seem to be happening.