I would trust Optodisc 16x media for archiving, especially OPTODISC R16 (+R). However, as with 8x CMC, that only applies if you get it under good name brands like Imation or Samsung.
I would not trust Optodisc 8x media for archiving, but it’s fine for everyday and non-critical use.
8x Optodisc was sold under a lot of cheap and crappy bands, and was more variable in quality.
16x Optodisc was a mind-blowing improvement, and I would put it head to head with TY or MCC any day.