Thoughts on Neutralaudio X-Drei, wrt BSG QOL

Thank you, Al. The X-DREI appears to be subtractive, whereas the QOL may be additive. As a result, I think it may process the signal less than the QOL which on another thread is possibly revealed to be a mid-side processor.
I think that if anomalies such as square waves in the ultra HF range are smoothed to correct sine waves this may reduce unnecessary load on the power amp/speakers and improve 'intelligibility'.
As a result I am tending towards the X-DREI since 2 units in series may be overkill.

So, the X-DREI merits so little discussion (your comments, Al, notwithstanding) as compared to the BSGT QOL which has had a TON of comments.
I'm a little confused as to how 2 units which claim to have such a fundamental improvement to sound quality and sit in the audio chain in the same place ie between pre and pow can have such varying interest levels from A'goners.
Both are obtuse in explaining their effects, and both have had limited reviews (X-DREI in 6moons, QOL in TAS), but X-DREI experience amongst listeners seems to be much rarer than the QOL.
A'goners, please post thoughts or this thread will go the way of the Dodo!
Marc

Blumlein laid out a lot of the fundamentals of stereo recording decades ago. He seems pretty spot-on; the closer one adheres to the basic principles, it seems, the better the sound.

I guess I still have to be convinced about the QOL.

With regards to the X-DREI, some equipment will benefit and others will not. I suspect this will have a more dramatic effect on solid state amplifiers, as RF switching is a bane of such amps, and something that could limit that might be really helpful if the amp has that sort of bandwidth to begin with. Tubes don't have switching issues so I suspect the X-DREI will have less effect on them, but its just a guess, the proof would be to give it a listen.

I guess that I'm commenting on the lack of user comments on A'gon. The X-DREI has had same overall limited coverage as the QOL (1 review each, minimal advertising), both promise substantial improvements over regular signal, but QOL ends up getting momentum of interest and X-DREI...nothing.
Surely all the QOL proponents should also give this unit some consideration. Note, I am not affiliated in any way with product, just getting my head around whether X-DREI or QOL, or indeed neither is way to go.
Will trial device in Summer myself.

Qol is advertising; is x-drei?