I've seen it posted many times that PLA needs to be stored in an air tight container. Some have even mentioned storing it vacuum packed and/or with desiccant packs, all with the end goal of preventing it from absorbing moisture from the air. Now I'm aware that nylon is a plastic that has a tendency to absorb water from my experience with italian motorcycles and they're frequently plastic tanks so I'm not ignorant that such things really do happen. I do have some questions regarding the effects of that absorption though.

in the case of a nylon fuel tank, water gets absorbed and will cause the tank to swell, often to the point that it no longer looks or fits properly and in extreme cases to the point that mating parts no longer seal correctly and leaks develop. Will PLA printed parts do the same? Will they expand and/or distort when exposed to humid environments? To the properties of the material change at all (strength, rigidity, etc.)?

I'm aware of the printing problems that come with using "wet" PLA but I'm far more concerned about the finished part rather than the raw material. Basically I'm trying to decide if it's worth buying some spools for a couple projects I have in mind or if I should stick with ABS for it's moisture stability. What about the other materials out there for FDM printers. Which ones have moisture related issues?