I don't see any down side at all to the creation of the new ("virtually") air tight PCGS holders. They also have a number of advanced security features as well. I am skeptical about many claims but not about the new PCGS slab....there's just way, way, way too much at risk for PCGS to claim it is made with certain features that it actually doesn't have. Therefore, there's no good reason for me to not trust that the new slab is virtually air tight. Logic and reason tells me that it would have to be....PCGS is not suicidal. Also, please provide me a link to the alleged 5-year guarantee for the Intercept bags? You brought it into the conversation and so you should have knowledge of exactly what that guarantee says or where it's text can be found online. My guess is that it's a guarantee that is so vague and open to interpretation that it actually guarantees little. But I am willing to admit that I have assumed wrongly if it turns out that the alleged 5-year guarantee is very specific and actually guarantees against any claim of degradation of contents inside the bag. Thanks for providing that info. As to experimenting with coins and storage products, I believe it was SilverPete who had done some environmental exposure experiments with fresh silver Maple Leafs. .