New lossless codec comparison (Jan '13)

What do you mean by 'that'? The average compression achieved or the observation that no codec performs much better on certain music? In the first case, I don't agree (see below), for the latter, I don't understand what you mean.

For example, take a look at the graphs (see the raw material ZIP) for Rush - Grace under Pressure and Howard Shore - The Hobbit: An Unexpected Journey. Both are DR 10 (see here for more information on DR), the average compression of the first ('80 rock) is about 70% and for the latter (2012 soundtrack material) it is 51%. As the DR measure is the same for both, a difference this large (19 percentage points!) can't be assumed to be side-effects of the loudness war only. However, still, the graphs look very similar when comparing codecs amongst each other.

edit: I just checked the replaygain values of both albums, for the first it is -7.0dB, for the second it is -4.9dB. That's a difference of 2.1dB. If we assume every 6dB (or 1 bit) of noise added halves the achieved compression, then "adding 2.1dB of noise" to the soundtrack would result in a compression ratio of 1 - ( 1 - 0.51 ) / 10 ^ (2.1 / 20) = 62%. This is still 8 percentage point away from the observed 70%, so I can't be all loudness war. But then again, ReplayGain is probably not a good measure either...

edit2: I just measured the RMS, for Rush it's -14.6dB and for Howard Shore its -13.6dB, so it's even the other way round: the one that is compressed more has a higher RMS in this case...