Finished up the episodes yesterday and thought it was fine. I was also one of the folks that thought Cowboy Bebop was fine (for what we got) given the source material it is based on and the near-impossible expectations of doing a 1-to-1 adaptation at this point. I put One Piece on the same level, but likely a bit more easier for most folks to watch and enjoy. Given what they accomplished, I think it is a promising entry for getting faithful attempts at more live action versions of other anime/manga properties (for better or worse).
Even though some portions of the story were modified/trimmed, I think they still did a faithfully good interpretation. Curious if this was a result of Oda being involved or he's just "involved by name" for marketing/fan confidence.
My biggest concern are the fights and their energy so far, especially Luffy's. It's going to get much harder to showcase as they dive deeper in the story because the fights he gets involved with increase tremendously in magnitude, energy, recklessness, and craziness. I'm figuring Luffy's fight scenes were limited (including screen time) to only a few moves/actions due to technical capabilities with production (and budget). I feel Netflix will greenlight a second season, but they have been notorious for killing additional seasons - so who knows at this point. I'd be neutral if this only got one season or if it got more pretty much.
Casting is OK so far. It's one of those series where you eventually start liking them the more time goes by. I'm still mixed on Luffy/Nami, but I'm sure they'll fill their roles as the story goes on.
Dedicated Anime/Manga Fans - They will definitely have some nitpicks and general consensus will be mixed.
Casual Fans and those not familiar with the manga/anime - I feel they'll generally find it watchable (or at least check it out given the hype/marketing) and/or like it enough to possibly check out the Anime/Manga. If there is a season 2, it is going to be a long ass wait - talking like 2025+.
The Live Action version isn't a replacement for the Anime/Manga and never was. It's just another outlet/medium to show current fans (and newcomers) what One Piece is about - even if it isn't a 1-to-1 adaptation. Although, if this gets multiple seasons - we'll see if Oda wraps up One Piece by then, otherwise might end up like Game of Thrones lol. One Piece does have quite a few arcs, so they could always end it on one of those safely.