Yeah, we've had this discussion before. Same old same old. Lots of assertions, but no supporting data. Negative feedback is bad because it causes time-domain distortion, distortions we can measure aren't important
Of course there is plenty of supporting data, and the distortions we are talking about *can* be measured, as well as heard.
high output impedance doesn't really affect frequency response linearity.
I don't know where you got that but you did not hear that from me. In fact the whole point of that paper (which now I am guessing you did not read) is that you have to **pay attention** to these things to **prevent** errors in 'frequency response linearity'.
so very high current amps are mostly for people that have more money than sense (like me).
Tube amps are for people even more skewed towards money than sense. ;-)
So, are you saying here that you have a tube amp in your future?? :)