On my system, I favour 4: (what I perceive as) dynamics and resolution are better; eg the big drum hits between 1.45 and 2.00 have sharper attacks and I could hear more reverberation; and the ?triangle hits and string plucks sounded cleaner throughout I least preferred 1, for essentially the opposite reasons stated above. I found it hard to distinguish 2 and 3, and would have trouble telling them from 4 if trying blind. I think I could distinguish 1, though, after some (more) time with each. UPnP via wifi to RPi-HiFiBerry Digi+ -> optical -> Modi Multibit -> Rotel RA971-II pre-out -> MCTH -> HD6XX. Minimserver was fussy with the aiff files so I transcoded them to FLAC - but not before having formed the 4 vs 1 impression. Different ripping software?