Interesting you mention CD tweaks. My local hifi dude gave me a tweak to mess around with this weekend. I have been trying out a black colored thin mat that covers the cd; essentially it looks like a very thin, black CD. I notice increased smoothness, a more natural analog-like sound with this mat in place. I also sometimes notice a lessening of dynamic contrasts and a little too much warmth. So some discs I seem to like it, others not as much. The effect is subtle, but overall one that I have liked. I was just researching CD tweaks this weekend to see what else I could dig up...