but that's not even the problem, the signal gets ringing or overshoot or takes too much time to reach a voltage or to go back to zero, in probably several parts of a complex circuitry. a good deal of those circuits are in fact implemented just to counter those unwanted artifacts(filters, feedback ...). it's a very unrealistic idea to think that the signal is what it is and that each component with slight imperfection will add an irremediable defect to the signal. nothing could ever be done in electronic if it really worked like that. that's an oversimplified wrong idea of a circuit. having one component misbehaving isn't like going to mp3. a deviation doesn't automatically mean a signal loss.
say we need one special type of component to build a particular system. that component always overshoot the desired voltage on first impulse and even the best component does it a little. if we have a way to supress that overshooting without bringing something worse whatever the value, why should we pay for the expensive slightly better one? I think the MIT videos on feedback show that brilliantly. take something super bad, add stuff, end up with a close to perfect sine wave. job done done!
I would even bet that often times, changing a system for a component with better specs could actually have a negative effect on the output signal. because the design and component values were taking the bad component response into account and compensating for it adequately. so when the error is out, or smaller, the correction components might bring it back in the opposite direction.
anyway, as always, if the output is transparent, it's transparent. I believe that tubes are useless relics of the past in audio, but when I see a tube amp with great specs, it's still a great amp. how a good result is obtained doesn't matter.