Tgb: Like Tonnesen, I don't know what you intend by that quote (it almost sounds like you're saying "statistics can prove anything"). We're only saying that A) you can't roll dice once or twice and learn how "lucky" you are, and B) tests need certain controls, like isolating variables and accounting for possible biasing effects, if we're not to be misled. You teach research methodology, you've got to know this better than me.
Anyway, I agree that you don't necessarily need an explanation if you perceive a positive difference; we just differ in our levels of satisfaction with not having a plausible explanation (or, having an implausible one), and in what we conclude from that about what's likely to be really going on. As I just posted on the other thread, most of the other tweaks you mention (filters, CD mats, even a plug-in clock) possibly have plausible methods of causation that could account for any perceived effects. It's the ones that don't (the CLC, the "Intelligent Chip") which demand the most skeptical scrutiny. You may not feel the same, but I'm curious to know how anything works, including in my system.
I also agree with the criticisms (from more than one direction) that overall, what we're trying to do is listen to and enjoy music (and maybe gear as well), not run "scientific experiments". However, some of us feel it is quite possible -- and important -- to find both truth in beauty *and* beauty in truth.