tom, i have no exposure to any class d. im old (ish) and stuck in my a/b ways. i am a huge fan of ati amps. currently i own a 300x7 & a 200x6. they are delicious. i see ati is continually paring their lineup to transition almost completely to class d. as i am respectful of Morris Kessler and enjoy many of his products i allow for, hmmm....is there something to this class d business? curious as to peoples perspective on the subject...when i saw your article AN EXPLORATION OF CLASS D...i had hoped for info on the n-core. to your questions...i know of no other n-core products. i mentioned ati due to brand affection. as to which of 'both' stereo amps of ati would suit me?.....the signature 6000 (300w)....however, i also lust after the ps audio bhk signature amps. whats that they say about old (a/b) habits?