^^ This will definitely have different sound signature. This is because of feedback and presence of that preset (470?) between both input jFETs. That not only provides DC null of output but also adds extra higher 2nd, 3rd order harmonics (depends upon minute mismatch of both P and N devices at input). So this could be liked by many of us, may be me too.
Now same thing is added by Mr NP in F5 turbo by means of P3 (200?) preset across input source resistors. This could add same kind of harmonics as I explained above. If excluded or set in middle, it will not add anything to input signal.
Now its clear to me why both F5 and this amp could have sounded differently.
PS: Please note that I was extensively researching the possibility and not have any measurements done. Also this does not dilute huge and nice efforts of OP. He still needs :clapping: for his work in this thread.