[Ghitulescu]

You see, probably you'll understand once that companies do the products batchwise, then move to the next product. The same is true for retailers and wholesellers. They don't buy 1 Verbatim, 2 TDKs, 3 Maxells, they buy one container of Verbatim. The PC shop nearby buys them in smaller quantities, you even less. There's a great chance that your disks bought today are from the same batch as those bought 2 years ago, because of this triple buffering. And if the containers were not empty, you'll buy the same disks also in the next 2 years. I assume all disks in one production batch are equal (they are not). But a batch of product A is different from the same product, if meanwhile the production line changed.

The visible drop in quality for Verbatim occurred when they changed from DataLifePlus to DataLife. There are no longer DataLifePlus, at least not official (but a lot of fakes). The last good product from Verbatim was the Archival Type (which was not so well received, partly because it was graded only 8x, oh, gosh, I wanted burn it at 24x for the price I paid).