Funny you should ask. This is what's wrong with them... (yes, that's my own review.)
I couldn't believe it when I saw this on the first disc I took out, thought that must be an outlier, but one was worse than the next. The holes you see in the pictures were literal holes in the reflective layer, pinhole sized, totally see-through. I thought ok maybe it'll work anyway and burned one, but of course it failed.
So that's those. At the same time I also tried the ones that are branded as M-Disc. I you think at almost twice the price per disc those surely must be better, think again – they're even worse. Again, it took my breath away when I noticed how the inner part of those discs looked. (And as I wrote in the review, those are _not_ scratches on the surface, this is all _inside_ the polycarbonate.
It's possible that both of those were intermittent issues, maybe a new fab they brought online, or some change in production methods, or whatever, but for archival purposes it's unthinkable for me to ever ever ever again trust anything from Verbatim, at least as sold here in Germany.
I _have_ been considering giving the Mitshubishi/Verbatim media sold in Japan a try, as it wouldn't surprise me if they sold completely different stuff there. Especially now that Panasonic has stopped producing (Feb 2023), it may be worth a try. Not sure yet.