Daxon, CMC, Sony, and many others are greatly improved with firmware T9. And, there have been some serious improvements to Daxon. For instance, now you can overspeed it and its playback is not "choppy" as before when oversped.
The scan matters (usually). But, the importance of it is media-dependent.
One may have a scan the holds 250 or so PIErrors completely across the chart with the occaisional visit up to 350. One may also have many PIFailures ranging upwards into the 20's. One may have 0 POFailures. That is about the limit of specifications. DVD is an analog media cut with a laser. Otherwise it does not differ from a vinyl record. It is then converted to digital, whereby a 0/off is 1/3 or less, and a 1/on is 2/3 or more.
Should errors occupy "areas" above the 1/3 tolerance mark, then the disc is said to be a coaster, or incapable of storing digital information. Movies on such a disc may still play, but you can expect the occaisional ski-sk-ski-sk-skip or "macroblock" or freeze from a set-top player.
While the amount of the PIErrors failures does not matter, their extent does. That should be less than 350 when scanned on a BenQ at 8x, less than 250 when scanned at 4x, less than 700 when scanned at 16x.
PIfailures matter in both their amount and their extent as seen on the chart. They should be skinny spikes and limited to 20 when scanned at 4x, skinny spikes and limited to 30 when scanned at 8x. If you see short, fat PIfailures completely across the chart (in addition to the normal spike pattern), it means that you probably have a communications failure between the writer drive and the motherboard. Lite-on did this to many of their customers by packaging a BenQ 1620 generic in the same box as an obsolete 40 wire cable. So, customers that have noisy computers got coasters.
PO failures should always be zero. Any amount other than zero means that the disc is incapable of storing digital information. Each PO failure will cause a freeze in a set top player.
That's my view on DVD specs as seen through the looking glass of a BenQ drive using CD/DVDspeed's QC test.
This popular scanning method views the disc.
It does not put the information seen on the scan to use.
CD/DVDspeed's Scandisc test puts the disc to work for a "real life" test. However DVDDecryptor in all-file mode with "ignore errors=off" is a faster, but less graphic real-life test. DVDShrink's "quicky" fast scan when you perform the "open disc" procedure is far faster than anything else, but not as effective. It is a popular timesaver with CMC customers who need to scan every disc.
Someday, I hope we will have a scan that reports the disc's specs (as in Disc Quality Test) and then reports the data file integrity (as in Scandisc) in just one single pass.
Today, getting all of the necessary quality control information takes two, time-consuming, passes.
Some medias get out-of sync between Disc Quality and Scandisc. With these medias, one of the scanning methods. . .really is meaningless.
While this does not relate to T9 firmware (problems have been fixed), let's take a look at Daxon AZ2 and CMC E01 when burned with P9 firmware.
The CMC media will always make a beautiful scan while frequently flunking the scandisc. It usually has good playback in a set-top player. I usually do not use the Disc Quality Test with this media because it usually burns in-spec. I always do a Scandisc or copy-back test of this media because of the nearly 10% data integrity failure rate.
The Daxon media will make some of the most frightening, nearly out-of-spec scans you've ever seen while always passing the scandisc test. With P9, it will often play back choppy unless burned at 4x (T9 is good to 12x). I usually do not verify or "Scandisc" this media, but I do use the Disc Quality Test because this media has trouble burning in-spec.
P.S. For discs that are great until the last few hundred megabytes, it is possible to reduce the target disc size in writing software. For instance, Ricohjpn R01 has ideal longevity, scans, data integrity, and playability. . .until the 4320 mark where it goes out-of-spec for PIF, then the rest may/may not be garbage. I set DVDShrink to a custom target disc size of 4320. Now the "entire" (smaller) disc it is now in-spec for excellent, repeatable results.
P.P.S. Whenever we see a beautiful scan posted on-line, and there is no scandisc test to go with it, we are looking at important, but incomplete information. Anyway, that's my view on it.