Based on what a friend said the sound of the XS was a huge step up in control and three dimensionality over the XA 100.5s. Never heard them myself. The bass is supposed to be immensely improved as well. This was on top of the line Avalon speakers but I don't know what. But for $85K they better sound great. But I wonder how it would sound on a more efficient speaker compared to the XA100.5s.
