does anybody watch/read it? You should, it's like Naruto if it kept the quality of Part 1 throughout the whole series.
The anime is definitely weaker (because of bad pacing), but i very strongly recommend the manga. It's the best manga i've ever read and it's getting better and better (Zou arc, the last one, is one of my all time favourite One Piece arcs).
Marineford, Enies Lobby and Sabaody Archipelago are some of the best i've ever seen (along with Naruto's Chunin Exams and Hunter x Hunter's Chimera Arc).