I am about to take the plunge and get the FRPP M-5230-5GTs and M-5251 - R X Pipe added to my 2008 GT. I have a quick question. I know on a lot of before and after videos there are comments about how the sound is not that different. I heard that it takes a couple of thousand miles for an exhaust system to be run in and reach it's full sound potential. Is that true of the M-5230-5GT (Stingers) also? If so is there a big difference?