I am getting similar results with my Icon Audio HP8. I hadn't listened to the Atrium since the Caldera arrived, but tonight put the Atrium back on my noggin and I can't stop smiling. The Caldera is pure bliss on my SS Cembalo Spring 1, and fantastic on my Icon Audio HP8. The Atrium is pure bliss on my Icon Audio HP8 and fantastic on the SS Cembalo Spring 1. Both eminently listenable, however, preferences exist. Speed on the HP8 with The Atrium is not lacking and the decay being a bit slower gives the sound such a wonderful tonality. The Atrium has flat out the best midrange I have heard on a headphone. The Caldera is every bit as good, just different. It counters with incredible speed, top end resolution and a more coherent overall picture. But, I sure do love the Atrium. I agree, the Atrium isn't as fast as the Caldera, but by no means do I feel like my music is slogging, and the tone is just heavenly. They are very different headphones and both deserve to be heard.