for the reasons i stated above, i’d worry MUCH more about CDs succumbing to this than DVDs, but overall, it doesn’t seem like a real-life concern.
it’s probably something that is statistically significant in testing, but translated to practical usage doesn’t degrade the disc very much faster than a non-labeled disc.
I also think that it is partially a marketing ploy…have you seen how expensive those specialized “cd/dvd markers” are?!
i’m not saying they’re JUST out to make money as I do believe the POSSIBILITY exists for the ink to degrade the disc, but as I said before, I don’t think it’s as big a deal as they’d like you to believe, and I’d worry about CDs before I’d start worrying about DVDs.