NFB is a subtractive process, although as proved by GE long ago, it increases the perceived odd order harmonic distortion. NFB removes some of the signal, and not in real time, either,due to propagation delay within the amp. Although I prefer to trust my ears, and could not care less about the theories involved, theory does match what I hear: with NFB it sounds less "alive". Deadened. Something essential has been deleted from the signal along with the improvement in distortion specs. There does sound like slightly less distortion, but the baby is thrown out with the bathwater. I personally think those who cite the "improved" specs from NFB are missing the point, but to each his own. Not so different from those who prefer SS over tubes, who often cite the "less distortion" specs. No, I don't enjoy listening to distortion, just unwilling to sacrifice aural immediacy to lower it.