I think that this 'classical' circuit can be fully classified as "Futterman Type". At the time, when I considered this option as a viable alternative to my "Modified Futterman", it seemed to me very attractive.
However, as I am quite suspicious about multiple feedback loops, I finally decided to do my way (one direct voltage feedback from output to input).
The simulated performance of this circuit shows a predominant content of second and third harmonic (see attached spectra).
In my opinion, the main simulated area of concern of this circuit is that there is significant time domain transient envelope distortion following the step application of the input signal (see the attached graph @ medium current level).
Best Regards
Luca Cellai
ecc230
