I was ripping some of my CDs with my AD-7201S. Of the ~25 discs I ripped, there were 3 discs that each had 1 track that could not be verified by Accuraterip (high confidence number with well known CDs), but the Test & Copy was OK. At first, I thought maybe my discs were deteriorating or something. But later, I ripped 1 of those 3 discs on an older PC of mine (BenQ DW1640) and the rip passed Accuraterip just fine. I'm not sure what to think.
Another thing I noticed is that my DW1640 is way faster. It's about 8x in secure mode while the AD-7201S is about 3x. The AD-7201S also makes funky noises sometimes, usually near the beginning of an EAC rip process, that I've never heard a DVD drive make. It sounds like the laser is repositioning loudly or something.