Let's put aside the unappreciated sarcasm about listening to Gallos with a stethoscope.
Since I don't have an accelerometer (what Stereophile uses to evaluate cabinet resonance issues), I had to make due, and I can tell you that if you listen to the Gallos 'frame" cabinet and compare it to a really inert B&W or recent KEF design at the same volume level, the difference is pretty striking. I think that "Spiritualized" is really missing the point - despite the 3.1 being a brilliant speaker and design, it isn't perfect and has one flaw - that flaw relates in part to one of the brilliant aspects of the design, namely the ability to have virtually no cabinet that creates diffraction effects that muddy the sound. That design approach requires a metal structure to support the D'Appolito array, and metal resonates (hello!). Even though Gallo I'm sure has tried to minimize that.
The issues is whether those effects reach any kind of audibility or not. The 'floor' for that varies depending on material and loudness, but most people feel that anything more than 30 db below say an 80 db foreground event is largely inaudible. Certainly anything 40 db below that is inaudible. Audibility is lessened if the material is an harmonic of the foreground sound. Of course, all this works in the favor of any speaker designer, and suggests that most of the time cabinet resonant effects are simply inaudible.
I did today a single blinded trial (comparing the two channels playing the same signal while I didn't know which speaker was playing - the stock one or the one with the applied anti-vibration treatment. Although I couldn't tell any difference between the two at lower volumes at really high volumes I could pick out the speaker with the treatment about 75% of the time, as the one sounding very slightly clearer. I didn't know which was which as someone else was doing the switching and was under strict instructions not to provide me with any cues. Some material didn't provide a basis for distinguishing the two speakers, but material with large amounts of bass however did. When I did my testing of the frame resonances, it is mostly in the bass that there is anything being produced.
I am still not totally convinced (75% over 12 trials is greater than chance but not that much greater), but I am happy with the results and they are easily reversible as the vibration dampening material peals off easily.
There is some science to this, but I don't have the equipment or the time frankly to due the testing. Hope this clarifies the issue for those who are totally skeptical. If you think this is just a crock, take a stethoscope, put on something at say 90 db or so, and start listen to how loud different cabinets are across speakers. You will be amazed at the differences, not just in terms of loudness, but in terms of frequencies.