I have done my tests under double blind where I have no clue what codec I'm doing. After I thought I could tell Vomir & The Rita at MPC Q5(88 ~ 132kbps) vs AAC/Vorbis at 160kbps with high/low anchors. I just did one few days ago where I thought I picked 256kbps MPC then found after It was done I picked the 128kbps as transparent copy. The puffy noise Vorbis has on anything with crunchy noise textures, Is from micro attack problems. The baron chamber which has noise burst near the end Vorbis craps out while MPC/AAC at 160k & MP3 at 192k sound fine. I've tried those samples before on HA since many were used to tune the LAME encoder in the past.
Same can be said with any well-designed encoder for post-MP3 formats with different samples from people with different sensitivities and preferences for artifacts. That's not unique to Musepack.
Musepack is proving what could've been if FHG pushed MP2 instead of MP3. Because I remember when that company said 128k MP3 >> 192k MP2, But then when quiet when MP3 could not cope with pre echo even at 320kbps. Even If 160k MPC can have slight artifacts upping the track to 256kbps can fix which can not be said for the MDCT based ones
Just like a lot of companies, Fraunhofer said many things. There was a claim of 128kbps mp3 reaching near CD quality in the instruction manual of the demo version of mp3enc released by them in 1998. Those marketing materials from nearly two decades ago are irrelevant in deciding which modern codec is the better one.
Also, techniques that reduce or hide pre-echo are implemented in MDCT based codecs. AAC LC uses TNS (moving pre-echoes closer in time domain to the transients so that those can be masked better) and uses smaller windows for transients compared to MP3. Vorbis has a more flexible set of window sizes from 64 to 8192 which are more flexible than AAC LC and MP3.
So using Neutron player and Foobar mobile don't count?. The Fiio M6 uses Android which you could side load Foobar mobile or Neutron on it. It not 2009 any more.
V2 Lame MP3 performs on par with other 4 codecs at 128kbps. So no wonder people can pick out 256/320 MP3 much easier than the other 4 codecs at 192kbps. But It is weird how Vorbis the worst performing of the 4 codecs to the right, can be worse than MP3 on most samples not used in that test.
Yes, I've seen that test. That result comes from
here. Hard to draw any conclusion from statistically insignificant results except MP3 from a single person.
To reiterate, I'm not claiming that Musepack is inferior. I'm just claiming that there is not enough evidence to judge Musepack to be superior to other codecs at higher bitrates. To verify that, a high bitrate multi-codec listening test involving multiple listeners is necessary. Without it, there are only speculations.