"Because McIntosh Tube Amplifiers are engineered to use Tubes in a way that does not rely on the Tube’s individual character and can perform perfectly provided the specifications are met, there is no advantage to seeking out expensive esoteric tubes"
I don't have these amps but he already stated that he changed the signal tubes and the sound improved , aka the character of the tubes came through, so why wouldn’t that also occur with the power tubes? I’m not aware of any tube amp, or other tube component where the character of the tubes doesn’t come through. I presently have 3 tube integrated amps, had a couple of others previously, and have a tube DAC whether it's the signal tubes, power tubes or rectifiers they all impact the sound in the respective sound. All their statement reads to me is marketing hype.