What I always liked is the highly technical arguments they employ after their listening tests
Superb definition and imaging are its strong suits. However, as a bonus, there is a sweetness and charm in and around the notes, which compels music to be even more realistic and suave. I hear this on some [but not all] of the over $2000 interconnects; this rightness on the overtones of musical notes is compelling. Add the textural integrity of the 600-SEIii to its superb imaging and excellent definition, and you have a solid winner at this price point and more.