I feel that the responses so far have overexaggerated a bit, so I'd like to add some input.

If you're going to ask whether or not you should watch One Piece in the One Piece subforum, of course you're going to get positive responses because the people who visit this forum are likely to be One Piece fans.

That said, although the One Piece dub is indeed what many would consider a botched or failed adaptation, the original show is still a shounen series. You would be more likely to enjoy the show if you go in without high expectations. This is not to say that One Piece subpar or is only for kids - some of the elements that emerge throughout the story can be appreciated by an audience of all ages. Personally, after I became accepting of the art and started to focus more on the comedy and story, I found the series to be highly addictive.

Some issues that emerge from almost every long-running shounen series is the presence of filler material and clichés that may be a turn-off as you progress throughout the show. If these don't bother you then there really aren't any other major drawbacks to One Piece.