I am getting ready to replace my stock speakers with Hertz components in front and 6.5'' in back. The fella at the store was running the sales pitch on Hushmat. He made a good case with regard to reducing rattles and helping the mid-range base. I have no prior experience with this type of product and was wondering if anyone has used it (or similar)? If so, did you notice a difference or any benefit? In the end, is it worth it?