Here’s a website (in Japanese) testing CD-R media by a Japanese CD freak
Interestingly, the most respectable Taiyo Yuden (“太陽誘電” is the Japanese name) did not gain good durability results – the tests shows under 14 different TY discs after one year, 6 of them does not degenerate, 2 of them somewhat degenerate, and the rest 6 significantly degenerate.
By the way, two TDK brand discs OEM under TY, both got significant degeneracy rating, whereas two SONY discs, both OEM under TY, got non-degeneracy rating.
I guess this may imply either the test was too strict, or TY does sometimes make disappointing stuff?
P.S. I guess the experiment is under humid Japanese weather