Other than what has been said in the threads on the subject, your testing may be the best way to understand the changes.
Jim,
Thanks - but since I cannot see the code nor really get a handle of how some values are being calculated - my testing will be blind.
Now - I did find this (courtesy of 6233638)
Dynamic Range (DR) - A measurement of Crest Factor, which correspond to the measurements at the Dynamic Range Database
Dynamic Range (R128) - A measurement of the track's actual dynamic range; the difference between how loud the loudest and quietest parts are.
Peak Level (Sample) - The maximum level of any samples in a track. This should not exceed 0dB with lossless files.
Peak Level (R128) - The track is upsampled 4x and then the peak level is measured. This is known as the True Peak Level, and can exceed 0dB.
Volume Level (R128) - Volume level analysis conforming to the R128 spec.
Volume Level (ReplayGain) - ReplayGain 2.0 values derived from the R128 data.
It's one in bold that interests me - It's obvious that any new tags that are part of v19 and R128 is used solely by MC and I am fine with that. But the if v19 tags being written that will be used by other players or devices are a mystery - that's not ideal at all.
I am still in the dark with respect to what v19 does to "old school" RG tags when a file is "re-analyzed" in v19. Presumably - the RG value that was there - and would be used in my iPod - is now changed to the value calculated in bold above?
As mentioned - I have a very large library and many dependencies. I simply need to know - in advance - what v19 is going to do to my files. Testing and seeing numbers on screen is one thing - but it's nowhere near a full understanding.
VP