ETLA, being an audio junkie with a collection of over 900 audio CDR's which I intend to archive for many years, I have mainly relied on the (2) top Japanese manufacturers; Mitsui Chemicals & Taiyo Yuden and Kodak. In addition, the durability of these blanks is among the best there is which is an important consideration for me because I play my CDR's over & over.
As most on my collection is .shn's audio files, sound quality is second to none. Consequently, I thought it prudent to note that unlike an analog tape, the actual sound quality will never vary depending on what brand of CDR you use and I have used almost all brands. Furthermore, the speed at which you burn audio will not make any difference in sound quality and I currently burn at 12x. However, one of the main variables which makes some CDR's better than others is their compatibility with different CD players, CD-ROM drives, and burners. For example, many older CD players, as well as many newer car CD players and portable CD players, will not play Maxell or some generics. Another problem with some blanks is that DAE does not work well off of them. If you try to copy audio which is recorded on a sub-par brand CDR, often you will end up with a copy that has annoying pops and crackling on it.
Shelf life before degradation has been discussed many times before.
Simply stated, if you want long life don't use generics, Ritek's, CMC, etc.