Yes, I attended the demonstration. Dan D'Agostino and Peter McGrath were there representing their respective companies as well as David Shultz from Transparent Audio. It was well attended and people were even browsing through the LP bins.
After some introductions and descriptions of the D'Agostino amp and preamp and the Alexia, Peter played some of his digital recordings. The sound was very good. In my opinion, it sounded much better than a similar system down at the NYC Audio Show a few months ago. In fact, it was the best I've heard the Alexia sound. It was very well balanced tonally, extremely coherent and it completely lacked any of the treble harshness and boomy bass that I associate with the Sasha. A solo piano recording and string quartet sound particularly convincing.
I will say this was a very expensive system. Transparent Opus cables throughout, the Alexia, D'Agostino electronics and an unfamiliar digital source.
The room was a bit over damped IMO, so the system lacked a bit of liveliness and dynamics, but otherwise it was a very good demo. The Alexias only had about 20 hours on them, so they will certainly improve with more break-in.
Mr. McGrath did a very interesting demonstration with the moveable tweeter module. He played some Nat King Cole and then moved each speaker's tweeter back 1/16th of an inch and played the song again. The voice lost some of its body and fullness and the image became a bit flatter. This was rather subtle, but after he moved them back to the original position and played the song yet again, it became clear just how sensitive this speaker is to proper alignment and set up. But it also demonstrated how much one can dial in the speaker for a particular room. There was a discussion about how the Wilson's adjustability is a real advantage for time alignment and flexibility to mate with a variety of rooms, but frankly, I've heard other speakers with fixed baffles sound just as coherent, clear and detailed.
I listen only to vinyl in my own system and would have preferred to hear at least some analog during the demo. The system was so revealing that with my biases toward analog over digital, I think, the differences between the two would have been quite apparent.
Overall, it was a really fun afternoon in a great setting. I appreciated hearing from Dan and Peter about their products and the sound was much better than I usually hear at shows. Fidelis hosted a wonderful event. I now think the Alexia is considerably better than the Sasha. In fact, based on this demo, it's the best Wilson speaker that I've heard.