Ripping DL DVDs at 16X is nothing. I've reported rips of up to 24X. At first I thought there must be something wrong with my Aopen 1648/AAP Chameleon Edition. The rips were so blazingly fast that it's unreal! I've done nothing to the drive and haven't used the speed fix that was discussed in the Aopen thread of this forum. The only change that I did was to flash the default firmware to 1.07 by TDB. Drive is set as Secondary Master. I strictly use this awesome drive for ripping dvds, cds, etc... (both protected and unprotected).
I have posted a question about the insane high speeds that I have encountered with this drive in the past in the Aopen 1648/AAP thread. However, if I recall correctly, no one really replied to it. Such high speeds, I thought that my drive must be defective in a good way.
Again, I consistently get 15X and up with this drive on all protected DL DVDs that I've ripped thus far. Average speeds range from 9.7X to 12X on them. At such high speeds, I'm surprised that all of my ripped DVDs burn and play fine without any missing files or read errors. Single layer DVDs rip entirely at no less than 15X.
From my experience, the Aopen 1648/AAP is the best drive for the money, and I've owned plenty of other drives from various manufacturers including Pioneer, Toshiba, Lite-on, Sony, Benq, MSI, LG, Asus, Plextor, Samsung, Hitachi, Panasonic, Phillips, NEC, etc...
I have the Benq DW1620 and other various Benq drives. All great drives, but I say again, Aopen is the fastest and most consistent out of all my drives.