Grey,
I agree, if they are "pleasing" artifacts, isn't that what we want? I am reminded of 2 things: an editorial somewhere once that said, "that warm sound of tubes is actually distortion"; and the "Tubehead" preamp that allowed a mix of op-amp and deliberately distorted tube stages. You could adjust the mix, which I bet would be different for different music.
That's why I asked about the difference in switching in the BOZ stage.