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

Like many things in this hobby, there does not seem to be a clear-cut performance hierarchy between TVCs, AVCs, volume pots, and discrete resistor switches/arrays. The reviews I have read of TVC and AVC offerings mostly paint them as nothing short of the crème-de-la-crème of preamplification. Reviews of EM/IA, Townshend, Music First, icOn, and Bespoke are all extremely positive. On the other side of the coin, I have read about their susceptibility to ringing, as discussed earlier in this thread, and possible difficulties processing complex, dynamic music. The many positive reviews left me intrigued enough to look at trying an AVC or TVC preamp for myself.

I have the icOn 4PRO balanced preamp here now. It is a Model 4b, which is fully balanced, including 4 Slagle autoformers, and offers both balanced (XLR) and single-ended (RCA) inputs and outputs. Functionally, it seems to be at the top of the pile of TVC/AVC preamps in that it offers fully balanced processing of the signal, remote control of inputs, outputs, balance, mute, and volume, and a very nice segmental display that is the easiest to read of any I have owned. Sonically, most of the reviews I have read are hesitant to call out significant differences between the better known options such as S&B TVCs, Slagle AVCs, or even the Bespoke TVCs. There does seem to be a clear preference (by many but not all) for silver wired TVCs or AVCs, which cost about twice as much.

I initially thought I would probably like the icOn as a passive volume control in front of my SMc Audio unity-gain buffer (using a Hatter discrete resistor passive preamp in that role now), but surprisingly the icOn seems to sound better as a stand-alone preamp connected directly to my amplifiers. Even though it has RCA inputs and outputs, in my system I seem to like the sound best when using the balanced inputs and outputs. One nice feature is that you can select which output (or both) are live, so I use the balanced outputs for my main amps and the RCA outputs for my two subs. Since I have only had the icOn here about a week, my final subjective assessment compared to the Hattor/SMc combination will have to wait, but I can say that the icOn sounds good. However, based on what I have heard so far, I suspect it will be a close call on which I ultimately like better in my system and for the music I listen to.

Like many things in this hobby, there does not seem to be a clear-cut performance hierarchy between TVCs, AVCs, volume pots, and discrete resistor switches/arrays.

You left out active preamps.

Its possible to direct couple using tubes to create a balanced output. IME when you do this you have transparency and bandwidth on tap that's very hard to get any other way.

When running balanced I feel its important to support the balanced standard (AES48) since it prevents ground loops and minimizes cable interactions.

That initial statement was intended to address the different volume attenuator options, as discussed in the OP.  My current rig includes a passive resistive unit into an active buffer.  The icOn 4PRO is a passive preamp based on Slagle autoformers.  It so far seems to sound better alone than it does run into the buffer.

I doubt the guide on grounding and shielding connectors in active equipment presented in the form of the AES Standard 48-xxxx (2019 Draft Revised), applies to the icOn 4PRO, since it is a passive unit. Fortunately, I cannot detect any noise issues when using the icOn.

My concerns are functionality and sound quality, and right now both options offer similar functionality and pretty good sound quality, which is up there with the many good preamps I have owned (including a tricked out MP-3). 

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....

@mrdecibel 

The only "test" is for me to compare the icOn AVC preamp against my current Hattor/SMc buffer set-up, for the sole purpose of determining which of those two options sounds better to me.  If the icOn sounded better through the buffer then that would be ok too, but that doesn't seem to be the case - it sounds better as a stand-alone preamp.  I haven't yet decided which will remain in my main system.