Meh. I disagree. The only differences there can be are SONIC differences. You have clearly articulated what SOUNDED off to you, and I can clearly describe what SOUNDS off to me with an amp that is not performing properly. But if somebody can't tell me what the sonic differences are and have to resort to the word "feel", then they are observing shit with their spider-senses. I get that sonic differences are more easily experienced first hand, etc., but once it gets to "uh, it feels different" and one can't describe, even poorly and inarticulately, what the actual sonic difference is... its not an empirical observation, imo, its an emotional/biased/whatever response. Which is totally fine. Play what makes you feel happy, regardless of the reasons. All of this is just passing time until death comes knocking on the door.