@BrianM
I get what you're saying. One of the many good things about Salk speakers, to me at least, is that Dennis has a major role in the voicing, and he plays with the Washington Philharmonic, so he knows how acoustic classical should sound. It is definitely a more demanding test than rock or pop where, as you say, it's harder to get a grip on what the true presentation really is.
@fsimms
I wish you could have been with us when we were listening at Dennis's. A lot of things could be going on (begin speculation theater). His room is fairly large and the speakers are several feet from the sidewalls, so that the speakers are not generating strong sidewall reflections. In that setting the high frequencies are radiating fairly cleanly to the listener, so the relatively greater extension and detail coming from the HT1-TL ribbon tweeter provide more clues about hall acoustics in the original recording than the SongTowers provide. However, in a different room with the SongTowers placed more closely to the sidewalls, it might have an apparent advantage. The SongTower tweeter (if I understand correctly) has a wider horizontal angle of radiation, so at the listener's ear the SongTower tweeter in the smaller room may generate some sidewall reflections that enhance the sense of spaciousness while the HT1-TL high frequencies may arrive without reflections. In that case the apparent SongTower soundstage depth might be greater. To beat the hypothesis to death, there are some speakers that have rear-firing tweeters that can be adjusted to provide varying amounts of rear-wall reflections to enhance the sense of the hall ambience. I don't know if that all makes sense (or is correct). But there are certainly factors that could cause one speaker to behave in the apparently opposite direction to what I heard, considering that the speakers are voiced similarly and the differences are not night and day.