The thing I like about the Zus on paper (having never actually heard them), in addition to their high efficiency, easy load, and supposed ability to go loud well, is that they use a single wide range driver for most of the sound, supplemented by a tweeter that crosses over relatively high compared to many designs, at 10Khz or so as I understand it. That is one of the attributes of the OHM Walsh speakers that endear them to me (they crossover at 8khz or so I believe), so the Zu's are a design that I would really like to hear some day.