I don't know if this is the correct place to post this, so I apologize in advance. Does anybody use the Ultrapro comic preservers, the ones with the board also sealed in mylar? How well do they hold up? I have a Strange Tales #69 that I've had for years, but have never really been satisfied with how I store it. It fits in the comic preserver, albeit very snugly, but it's not a comic that I want to handle a lot anyway due to it's age and condition.

Any longtime collectors use these, and how would you rate them?