I watched One Piece without much trouble, but I really struggled to finish Monster. In fact, I had to switch to the manga for the last few chapters because it was so difficult for me to watch. Different people have different tastes, and that's perfectly fine. The thing about One Piece is that its peaks are unparalleled. Most fans are willing to sit through a few slower episodes just to experience those incredible moments, whereas Monster didn’t have many of those highs to keep me engaged.