A transfer rate test is a useful test, however it is useful for different reasons than a PI/PIF test. It will tell you if the data can be read, and at what speeds it is being read at, nothing more. A PI/PIF test will give you specific numbers of errors which, depending on their concentrations and levels, will tell you the general burn quality. Both tests have their place and if you want a thorough test of a disc, doing both tests would be ideal.
To make an obvious example of the value of PI/PIF tests over transfer rate tests in some circumstances, I’ve used similar cheap generic tests to these (including VDSPMSAB), and they generally have very high PI/PIF levels when burned, however they often give perfect transfer rate tests. Now take a TY disc with a great PI/PIF test and an identical looking transfer rate test. If you are judging your burns and trusting the disc’s likelyhood of holding up over time by the transfer rate tests, the test results between TY and cheap, generic discs will be identical. Of course you and I both know that the fact that the PI/PIF scans of the generic discs are far worse than the TY’s PI/PIF scans tells us that there is a much greater likelyhood of having problems with the discs with the far worse PI/PIF tests, even though a transfer rate test may not necessarily show it.
Yes, his transfer rate tests are less than perfect and are a general indication of ‘somewhat shaky but useable discs’. The PI/PIF tests will almost certainly translate the same though, the PI/PIF scans are undoubtedly fairly poor and would indicate just the same thing, ‘shaky but useable discs’. Rarely will an excellent PI/PIF test translate into a poor transfer rate test (especially with the addition of jitter level measurements as well), just as a fairly poor PI/PIF test will nearly always translate into a poor transfer rate test. The advantage of PI/PIF tests is the reporting of actual error levels throughout the disc. Without it, one could argue that TY and Princo are equal if both have perfect transfer rate tests (which would actually hold true if based only on the discs’ current playability and nothing else).
I have a few discs that are now unreadable that I backed up when they were still readable, some with perfect transfer rate tests no less. Why did I back them up, even with good transfer rate tests? PI/PIF tests told me that the discs had elevated PI/PIF levels. I often suggest that people run transfer rate tests and I run them myself a fair amount, but PI/PIF tests have some definite advantages, especially when you become accustomed to how PI/PIF levels translate into a disc’s quality and probability of playback ability.
If you want a rough ‘yes’ or ‘no’ with little room in between for judging a disc’s quality, a transfer rate test will give you that kind of indication. If you want a more specific translation of a disc’s burn quality, a PI/PIF would do a better job of that. Without PI/PIF tests, all different types of media would more or less be defined by either ‘great’ or ‘horrible’ with little in between.