I do not have superior manga-reading ways, but I do question the sanctity of people who are used to exclusive shonen manga.
The reason why One Piece has a lot going on because it's actually cramming a good amount of story into a single chapter, like every other serialized manga out there that doesn't drag out every battle into a volume's worth of content like Bleach or Naruto does.
I really don't see much of a difference how One Piece is structured than something like Berserk is. Aside from Berserk being a million's time better, in terms of content and execution both are fairly traditional in terms of manga, sticking to formulas that have been working for decades. Vagabond is a bit nontraditional, but has such exceptional story and character development that it fully works of it's own intent. Then you got Bleach, which is pretty much an anime storyboard drawn to look like manga, which to not knock Bleach down happens a LOT nowadays to action shonen (even seinen sometimes), but Bleach doesn't even have anything remotely of value to make the long drawn out battles worth the wait so it's style is pointless.