Best tweak

Rubber (soft) door stops? Hm.... I'd try something of the same height that's more rigid, and listen for better temporal performance.
My favorite tweak involved hanging my Class A monos under the basement floor joists: thermal, acoustic and visual isolation in one shot! Enjoy the music.

subaruguru... can you explain the basement idea? is your system on the floor *above* the basement with cables running up thru the floor?? what are you hanging the amps with? what sonic advantages did you notice?

I'll second Ernie on this type of isolation tweak. I installed the electronics for the living room setup in the hall closet. Very little air born vibration and a lot less coming up from the floor. Also when the lights are out and the music is on, no glowing LED's or tubes to distract me from the music. Another bonus is that I can suspend and organize the cords and cables for the best sound as they are not in plain site.

Taking off ones glasses. (Even with the lights off and eyes closed)