Mike - Typically it will be a little deeper throatier shound... more of a finely tuned sound if you would. And then it will depend on the mufflers you have.
Thomas - I had my Super comps Ceramic coated and it was worth every cent (even though I got a killer deal) I would have paid double. They still look like I just installed them! And they were looking tired before! Under hood temps seem to be better now too! I'd check with all the local plating places and see what you can get done?