I believe you should read it. Because its an epic adventure.
Yes it is long, Yes it does have this huge fanbase that gives it a somewhat "negative rep", but I assure you its a top notch manga. This is coming from a reader of serious manga's like Monster, Berserk, Claymore etc. (That doesn't really say much though).
But yeah, the mangaka Eiichiro Oda is a genius.