There have been many positive reviews of the NC1200-based amps but for another perspective, read near the end of the linked review of the Mola Mola Kaluga.This review perfectly describes my experience with ICE Power.
http://www.monoandstereo.com/2015/08/mola-mola-makua-and-kaluga-review.html
In learning about Class D, it appears that after the linear signal is destroyed and turned into a saw tooth wave form, the output filter? tries to put the signal back together...doing an incredible job considering the complexity of this task...but ultimately is unable to restore micro details to recreate the original signal...which people such as myself notice very quickly, while others either don’t notice or enjoy the new coloration.
Perhaps my understanding of Class D that I mention above is incorrect and someone can correct me.