I started the process of ripping my CD's to hard drive in WAV format.
Found that my earliest made in West Germany pressings for Mercury have higher error rates. One of them is mostly unusable at this point. Luckily I have a MoFi version of the same CD, so no real loss.
Do not see any CD rot, but the errors are there.
Alot of them are not well balanced and vibrate. They have to be read more slowly by the transport.