A few years ago, a local dealer had in the Ars Aures Sol (in referring to the speaker, he shortened the name to the unfortunate, "Ars Sols"). I thought that these were quite nice sounding speakers. They had a reasonably lively sound without being overly prominent in the midrange. The expensive "Revelator" tweeter on the speaker was particularly nice -- fast and detailed while still being quite smooth and non-fatiguing. They must have been reasonably efficient because they were being driven by pushpull triode amps (300B or 2a3s).