Hmmm, longevity, how long is a piece of string?
More to the point I feel is the question, is media produced by CMC for other companies such as TDK etc etc etc better quality than there own.
TDK at the moment are using three different manufacturers, Mitsui, Moser Baer and CMC.
The Mitsui ones at first glance look and feel really good, you now that feeling when you are holding what looks like a good product. Now on closer inspection some of these have silver flecs in them, I have no idea what these are, but they burn OK and look OK in Nero CD Speed, no errors shown in Data or Audio burns.
The top side of the Moser Baer and CMC ones is somewhat blotchy and not well finished at all. I wonder if TDK are aware of these issues I may drop them a mail.
I have had some CDRs rot away, these are not very old and are TYs
Sorry to ramble on, but with no control over the media producers it seems we have to pay our money, and take a chance on what we feel is the better quality media.