I think that the point being made is about the sound in absolute terms -- not the actual music, etc.So the answer to my question is, "yes"? You are using different recordings of different performances to compare systems.
If I understand correctly, in comparing the overall sonic result of an optimised analogue and an optimised digital sytem -- both playing excellent source material -- the analogue will sound superior.
I.e. according to Bonzo, an excellent analogue recording played through a system optimised for analogue, sounds better than an excellent digital recording played through an optimised digital system...