[byproxy]

In my own testing the only thing that stands out in null testing is artifact noise and stuff that's lost in the higher frequencies, i.e. cymbals. The more compressed you go, the more artifact noise introduced and high frequencies lost. As someone who can enjoy classical music (for simplicities sake "classical" and not some other classification), I notice that a bunch of "audiophiles" seem to think that's where their money is going - to increased listening satisfaction of classical - when that tends to be the type of music where least is lost in compression. Music with constant cymbal hits (e.g. rock music with drumkit) seems to lose the most.

Again, my own personal null testing with music spanning various genres in my library.