According to several studies, notably a recent one conducted by C’t, this is true.
Many people have problems with CMC DVD media but it’s not stability. Poor firmware support from the drive manufacturers is the main issue, actually. As I mentioned many times, I also thought CMC was crap until I burned some CMC MAG AE1 in a NEC 3540A drive. This is a great combination.
CMC discs either burn well or not, but if the burn is OK it stays that way.
Burn quality and stability are not directly related, at least it’s not a clear cut as many like to think.