Close. Every individual drive will show a reading "preference" for some media, some read speeds, and even for media burned at a specific speed. Different firmware versions will also affect reading to a small degree.
This is one reason why we keep saying that you should not compare scans done in different drives or different firmware.
Consider what is being reported in a scan, and how. There is no "strat" for this, only the way that the laser focuses on the disc, and the way that particular disc reflects the light. Firmware changes that affect the performance of the drive mechanics will most certainly alter reading performance as well, as most of the mechanics are the same in reading and writing. Only the laser power calibration varies in writing, not in reading.
But the bottom line is that a really good burn will scan well all the time in every drive. Those discs that are "middling" will produce the widely varying results that are the subject of this thread. These, and the crappy burns, are the ones that separate the good readers from the not so good.