@whart , I am very familiar with the HQD system having personally replaced 3 ribbons and two toasted Quads from overexuberant use of the go knob. They sounded so effortless tied to 6 Levinson amps, all the way to death. They were far from perfect. Their image was not realistic probably because they had an inconsistent radiation pattern going from point source to line source back to point source each driver with different dispersion characteristics. We made a system with stacked Acoustat Monitor 4s and RH Labs subwoofers that was so amazing I continue to use that format 40 years later.
Although you did not specifically invite me over, I have been invited to the Ducati Tent at next years MotoGP race. I also intend on seeing the Formula 1 race at some point. The Circuit of the Americas is in your back yard I believe:-)