I liked the photograph of the interior of the QSub. I missed where JV described the issue of the placement of the sub within the room. I assume there was only one sub, but I think at Magico, where he heard the M3, there were two QSubs. I wonder how an all out Q7II plus two QSub15s plus two QSub18s system would sound compared to the various reference level four tower speaker systems like the MM7, YG, Genesis, WAMM (plus tower subs) or Pandragons. One does not read much about Q7II based systems, with or without the QSubs.
I agree that it would have been interesting to read about the Qsub/MPro combination. But if that MPro is up on the third floor, getting that Qsub up there would be a challenge. I did not know that Valin has different listening rooms. That would explain, in part, the very long list of his reference components.
Will there be a future MSub tower with M7 super system? With the digital integration controls, that might be one incredible system.