I have heard both speakers on several occasions, the T.1's with field coil drivers are very special IMO, and worth seeking out an audition to form your own opinion.
During me decision to purchase T1s which took well over a year, I auditioned the T 1s with various amps, Atma-sphere, Shindo, and Esoteric, and a few different cartridges Air Tight Supreme, Air Tight PC-1, Van Den Hul Colibri, and a Koetsu Coralstone. The T'1's easily resolved the character of each combination.
I find these speakers to be very transparent to the source, they convey tone colors much like an electrostatic speaker, but with huge dynamics. They also really allow the energy of live music to be conveyed in a way I have heard very few other speakers. Despite being "lively" there is a smoothness about them. In hi-fi jargon that seems like an impossible combination, lively yet smooth. I suspect this type of sound is what field coil drivers bring to the table. I will leave that part of the discussion to the technical people.
I have heard vocal, folk, rock, large and small scale classical music all done to my immense satisfaction on the T1s. These speakers allow you to explore all genres of music, instead of gravitating towards a narrow type of music which many systems tend to gravitate towards. Some of my former systems are included in that generalization.
Since these are horn speakers it is worth mentioning that they can convey a wonderful vocal without the typical mega phone horn sound. When I heard vocals with a Koestu at the helm and Atma-sphere driving, it was a very special combination. The midrange "sweetness" of a Koetsu was very complimentary to the Classic/Atma-sphere combo, which if it needs anything it is a slight sense of "sweetness". Perhaps adding the Koetsu is a coloration, but in this combination it is magical addition....to me. However, what really sold me on these speakers was with the Air Tight Supreme at the helm playing classical music. For me that was the first time ever on a stereo system I was able to really enjoy large scale classical music. It was large in scale, dynamic yet had a sense of delicacy. I was done once I heard classical music on these speakers.
In summary, these speakers are not a one trick pony, they shine on all types of music and at low and high volumes. These field coil Classic T'1's, are something special, and worth jumping on an airplane to audition.