Stranger still that people can even perceive these differences. I've noticed zero changes between them and these are very slight tweaks, shouldn't suddenly make any vintage style amp sound awful.
In fact, I would be curious if Cliff could put out a FW 18.11, with zero actual changes, and if there would still be people who said it sounds better/worse.
My perception of my tone changes day to day. My hearing, my guitar tuning, how loud I'm playing, my mood etc all varies a bit. I think this has way more effect than anything else related to the hardware
The Placebo effect is very powerful with audio. I have experienced it first-hand, when I have been tricked by friends into thinking I could hear a difference between 'A' and 'B' , when in truth it was exactly the same material.
There are other psychological factors at play also, such as the pressure to conform with your peers.
Once, I was at a local hifi shop, and the salesmen (there were 2 or 3 of them iirc) were demonstrating the 'Bedini Clarifier' which is a gadget that spins CDs around and somehow "clarifies" them. I was sceptical then, as I am now, and I knew that there was absolutely no way that that thing could work. Yet, when he played the CD, then pulled it out, "clarified" it, put it back in the player and played it again, I could have sworn that it sounded like a curtain had been lifted from the speakers. I am not a "true believer" and i think a lot of audiophile products are snake oil, but I still need an explanation for what happened that day. I think it was the fact that i was surrounded by true-believers, and I wanted to keep the interaction polite, so my brain subconciously made me fall in line with their expectations of how I should react.
I think a similar phenomenon happens here on the forum, sometimes. (I'm not condemning it in any way - it's just human nature.)
Anyway, our perceptions of audio are very malleable, and external influences can really mess with your ear.
