I remember my first encounters with the Thiel 3.6 at a local high end store, in the 90's, where I got to play a bunch of my CDs.
I had the distinct impression of "that's exactly what it sounded like" when the music was recorded, both in terms of the character and liveness of the instruments, and exact character of the recording itself, and no obvious character/resonance etc from the speaker.
I think it was one of my first encounters with a really neutral, accurate sounding speaker. I'd had a similar impression listening to Quad ESL 63s, but it was the first time I heard that from a "box" speaker.