Well, these are, simply put, as good an amplifier as Morris Kessler knows how to make at this time, hence his decision to stamp his signature on them
Will we hear any difference vs. the AT3000 Series or Emotiva's Reference or even X Series for that matter? The vast majority of the time, likely not. But I appreciate the dedication to reducing all possible forms of noise and distortion to the point of virtual elimination.
Creating an an amp design that uses a single input stage but then uses balanced circuitry from input all the way to output, while remaining stable into extremely low impedance loads, that's, in many respects, very inefficient and costly; but it's also the absolute quietest design possible. Anthem doesn't bother trying to keep the entire amplification circuitry balanced from input to output; they're more concerned with being fully stable into all impedance a right down to a short circuit. Well these ATI Signature amps are aiming to do the same thing, but maintaining that fully balanced circuitry the entire way through. That requires more than double the electrical current (due to heat losses), hence the dual 20 amp inlets!
So these AT6000 amps really are "no holds barred". These are about being able to drive ANY speaker with essentially zero noise, no distortion, and never a trace of current sag. Is that necessary? Heck no! Buy reasonably designed speakers and this sort of output capability will never even approach being necessary. But these are about Morris Kessler saying, "whatever you've got? Bring it. These amps will power it, and they won't make so much as a peep until the signal says to."
Some nut job out there undoubtedly wants to drive a full range ribbon that dips below 1 ohm. These'll do it. You just need to require your house, too, is all
