Haven't read all the posts here, but I'll chime in for a quick second to say that racks definitely influence sound.
I've never owned a nice rack, but I used to have my system on a cheapo tv unit... Moved it to another cheapo Ikea tv stand...the thing looked nice, but was hollow on the inside. Well, wouldn't you know it, the system took on a 'tubby', 'hollow' sound coinciding w/ the rack on which the equipment was sitting. Upon switching everything back to the old rack, everything snapped back into place audibly speaking. I further experimented by putting equipment on tempered glass and lo and behold, the system took on a bit of a sharper edge.
I am a firm believer that the item on which equipment rests influences its sound character beyond a shadow of a doubt.
I've never owned a nice rack, but I used to have my system on a cheapo tv unit... Moved it to another cheapo Ikea tv stand...the thing looked nice, but was hollow on the inside. Well, wouldn't you know it, the system took on a 'tubby', 'hollow' sound coinciding w/ the rack on which the equipment was sitting. Upon switching everything back to the old rack, everything snapped back into place audibly speaking. I further experimented by putting equipment on tempered glass and lo and behold, the system took on a bit of a sharper edge.
I am a firm believer that the item on which equipment rests influences its sound character beyond a shadow of a doubt.