Anything you do with a system will change the sound. Try 4 firm tables under a piece of gear you will gear different presentations. In the end, changes are only good if you like what you hear, but in my experience, those who design products know a heck of a lot more than I do. From being in electronics I know if you put a dale metal film in where carbons were in that particular design, knowing metal films do pass highs much better but by doing so all you wind up with the sound skewed to the upper end, and sound is bright as hell and out of balance because that circuit design was built around what carbon films did so it was already compensated for in the design circuit to achieve proper sonics and balance of highs to the rest of the range. Now if a designer uses such parts (metal films or whatever) in their design it will sound fine because they have also compensated for in their use in their circuit design.