Pfft, that's bullshit.
I'll trade an episode of Madoka for 4 One Piece episiodes.
I don't know much of Madoka cuz I planned to watch it some time in the future...distant future...
But as for One Piece, the further you go, the more you can't believe how well thought out it is. The first 53(60?) episodes are like a prelude. Like, if you watch the series, the first 50-60 episode get better, and better, why? Because Oda tells you so much in those episodes, that you just don't pay attention to. After reading over 700 chapters, I go back and reread the beginning, and I STILL CAN'T BELIEVE THIS SHIT! There's a reference in the first 10 chapters to a character introduced in the 500s! Doesn't even end there, as the story goes on, everything preludes the future. There was a reference to a place around chapter 300?(not sure) and it comes back up around 600.
Telling me to trade a 12 episode anime for you to watch 20% or the prelude hmph! I might do it if you watch the first 50. But that is all on you. I'm not saying Madoka is any less of a story, I'm saying that it's just not proportionately fair imho.