These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Arc Fatigue: Musashi's travel after his fight against the Yoshioka. The action in the series has decreased a lot and Kojiro has appeared for only few chapters.
Magnum Opus: Generally considered to be this for Takehiko Inoue. Although Slam Dunk was ridiculously huge Breakthrough Hit for him, Vagabond really impressed everyone with its nuanced character development, sophisticated storytelling and masterful art. Though Inoue himself has never said it outright it's quite plausible that he also considers it his best work. He has said that it has taught him a lot, and that he is afraid that he will stop growing as an artist when Vagabond ends.
Narm: Every single time Kojiro tries to talk and ends up saying Aaaaa and Auaaaa.