TLDR version:


Even if a filament is stored "correctly" and comes from the factory "dry" in a vacuum sealed package, it will still potentially pick up enough moisture to give you inconsistent print quality. Especially if the seal has even a tiny puncture.

In regards to the comment on the other page about how you shouldn't have to dry it straight out of the package, I can tell you that we used to buy pre-dried nylon resin. It gave great results in the first half hour to hour of running, after that it would pick up too much moisture from the atmosphere and result in junk production. Even in a storage/feed unit kept at 10% RH (like so many I see on these forums) it will still pick up moisture beyond acceptable processing levels.