Well, i gotta eat my words, the live action adaption is actually good.
They nailed the main cast (although Sanji has to little screentime to fully tell)
They (mostly) nailed the support characters like Zeff and Garp
The (mostly) nailed the enemies.
Especially Buggy, holy shit the actor carries the Buggy episoded hard.
Few things that irked me, though. First, the pacing. You can say the manga has the pacing of a snail on weed, the adaption almost rushes through the story.
But i can understand that doing stuff is expensive and that after Cowboy Bebop Netflix wanted to be a bit more careful with the budget.
Second, some optical changes i don't get. They gave Garp his stupid dog hat, they put a wig (or made the hair) of Helmeppos actor as dumb as it was in the manga/anime. Put on a nose prop on Buggy's actor that he constantly has to wear.
Why the heck didn't they give Usopp at least a nose prop to make his nose a little longer? They even went so far and gave his personal Jolly Roger a small nose.
Same for Sanji, why no curled eyebrows?
If they're not willing to go this "far", i can only wonder how they plan to adapt Franky, or if it really runs this long, Jinbe. These actors won't be able to just tell them "Oh btw. no face props, kay?". (Brooke and Chopper are left out 'cause they need to be CGI'd to even work at all)
And finally, yeah you can guess it, the Fishmen.
Look, i know GCI is expensive. And it's rather impressive what the prop people were able to come up with on those actors.
But they simply look bad and goofy. And due to the props, all their movements were somewhat stiff, and they had partially CGI the movements, attacks and fights to begin with.
I hope Netflix ups the budget that the showrunners can go for CGI Fishmen and Merfolk in future seasons.
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E: Also, cool little tidbit:
The german dub uses (mostly) the same VAs that the anime does. There's a few where i'm not sure about, like Zoro or Corby ... but that could be me. Zoro had a VA change sometime after ... i think Skypia because the original VA passed away after an accident.