My 16a7 has big trouble reading the second layer of an old scratched commercial pressed movie. My 1693 and 165h6 scan and read it well.
Here are four pictures:1. Disc Quality scan on 16a72. Disc Quality scan on 165h63. TRT on 16a74. TRT on 165h6
I just noticed my 165h6 runs the TRT at a slower speed, so here are the results from my 1693. As usual, it reads the disc better than any of my other drives.