Is an autoformer (AVC) always superior to pots and resistors ?

TVCs, ime, rounds things out and softens transients, but like everything else, it is what your ears like. TVCs are supposed to be better with impedance matching between source and amp.

@sns, Mitch is correct, it is not the same. I am speaking unity gain, and my experience is exactly as stated. @mitch2, with a unity gain passive device, the gain is provided by the source, your last statement is unclear to me. sorry....... 

@mitch2 I apologize for my misunderstanding. I commented based on your statement " where the only gain ( if any ) comes from the autoformer transformers themselves ". If designed with +6 db gain, yes, but we are talking unity gain, so the source creates the gain. My best ! Always, MrD.

The Statement sounds like it does everything well. However, I have eliminated tubes from my system. Enjoy ! My best, MrD.

Mitch, I think using an additional set of interconnects, vs the icOn going direct into amps, might make this " test " invalid to the discussion at hand ( apples to apples / apples to oranges ), although, what ever sounds best to you. My best....