Kinda hard to push either past their limits in most domestic listening environments, though.Saying a Purifi 1ET9040BA sounds better than, say, an NC502MP is subjective and falls apart in the face of measurements when both are used within their designed limits.
But of course when one amp is pushed past its limits compared to one that isn't there can be audible differences (distortion, clipping), no one ever argues against that.
I know I could not tell apart a NAD M22 and a Benchmark AHB2 no matter how hard I tried, and that's cured me from trying to tell differences between top amps ever since, and kudos to whoever claims they can.