Honestly, despite being a huge One Piece fan (or perhaps because of that) I wrote the show off on concept alone. One Piece has far too many outrageous physical effects which are actually important to the story, that can never be captured by live action, such as how character sizes can vary significantly throughout a scene to emphasize that character's impact upon the narrative at the moment. A lot of the physical comedy and timing has already failed to be translated to the anime, so the live action won't do that any better, being another 'animated' format.

All of that said, I'm actually happy that the live action exists. One Piece is as successful as it is largely because the story is not just good, but actually contains some really damn important philosophical concepts. If a certain percentage of live action viewers will find themselves drawn to explore those ideas in more depth, where otherwise they would never engage with such things, that would be great.

Also, apparently the legendary Studio Wit is producing a total remake of the entire anime with a strong commitment to making it top quality. So die hard fans do have something great to look forward to themselves.