The difference is, as they were released people thought it was just a part of the story. No one knew how long it would be. Now on the other hand, you read a few and think, wow there's so much more. The story is amazing, but not if you think about the length before context. Before, people thought about context without any thought to length. It was called a prelude AFTER the chapters that made it so came out. At the time, it was the start, rather than a prelude.
Many got past the length, honestly, a couple years ago I'd say after the Arlong arc. That point slowly moved to the Laboon Arc, then the Water 7 Arc, then The Archipelago Arc, then the Whitebeard War, and now I honestly don't think people can feel the experience til after the Mermaid Arc. It's a story that just gets better as one continues. Again, if someone thinks about the length, and complain about the artwork the entire time >.>
It'd be like if I watch Madoka with the mindset, 'Sailor Moon with a twist'.