Autoformer versus Transformer Passives?

Working on getting the new Slagleman's. These are sold by Intact Audio. Sort of a "nude" version of a non-remote TAP-X. I'd like to compare them to my Lightspeed and hopefully can remember enough about the S&B MkI's to make a reasonable comparison. I'll let you know the results when I get them and have had enough time to listen.

I have spoken with Dave several times and made a few autoformer preamps for friends, using his and Pieter's autoformers.
Transformer passives have more bass distortion as compared to autoformers. This is easy to confirm: look up the low frequency response graphs at S&B and Sowther sites, also, Jensen line input transformer data sheets, including % of harmonic distortion at low frequencies. A magnetic core will saturate and distort with a combination of very low frequencies AND high input signal levels.
OTOH, a transformer's galvanic isolation is great to get rid of ground hum issues, it also attenuates very high-frequency digital noise such as the normally unfiltered SACD outputs or out-of-band DAC artifacts.
IME, autoformers have great bass, outstanding headroom and can be made to roll-off smoothly at ultrasonic frequencies.
In summary, IMO, if your system has ground-induced hum, or an SACD player or your CD player outputs digital HF nasties, use a transformer volume control.
IMHO, if your sources are clean of HF noise and there is no ground-induced hum, an autoformer is a superior solution across the board: bass, dynamics, low level detail, frequency response, distortion AND musicality.
My 1c worth (adjusted for recession)

I asked John Chapman (BENT) about the ground-induced hum before I chose the autoformer over the transformer (he had a few S&B still available)and he said that in most cases that should not be a problem - I hear no hum so I imagine I'm safe on that ground. I'm not hearing any obvious HF nasties from my Accustic Arts DAC so hopefully this is a pretty good application for me. I would love to have A/Bd them but that was not possible.

I think I've mentioned this before, but I built my own linestage using S&B mk3 transformers from John. I tried wiring them up as autoformers, as mentioned on some forum. There was a very slight difference in sound but, in the end, it was more important for me to use balanced connections with higher gain. It would take 4 autoformers for balanced I/O.

The autoformer wiring did seem to have a bit more deep bass, all other being equal. I also have the ability to turn up the gain on my bass amp to account for that. My Genesis 350's are not lacking for dynamics and bass but would certainly reveal if there was an issue in the chain. Easily (and queezily) capable 0f 20Hz test tones.

Comparing the Slagle autoformer to the S&B would be a different story.