Been there ....done that. I have always had the Borla "S" catback. Catted X-pipe and man it is the sweetest music ever no matter what RPM. Thru-out the entire pull and down shift just absolutely hands down best I ever heard and I am not just saying that b/c it's my car and exhaust.
I am one who will call it like it is even if it's a bad move on my part. So, The story is I bought an O/R-X and put on my car for what amounted to couple months. Car was so loud it was insane. Alot of areas in driving and getting in to the power it sounded not just loud but like you said raspy and like **** compared to my current and before set-up. I ran a Cam tune and the only part of it all that was sweet is idle and probably 15-18HP gain. Now the HP I hated to let go,but I figured out that there was 2 choices. 1. Get somebody to trade me there GT500 axlebacks for my Borla "S" axle back sections and of course a little money from whoever. I then would be "probably" rid of the race car loud and rasp ...maybe. 2. Pull the O/R-X and put it back to catted X and ****-can the cam tune. I could not give up my borla....Well I switched back and at first I thought I surely had ruined my Borla's. Car was quieter. Like quieter than before all the changes. Now my sweetness is missing.I thought fuel dumping/No-cats had scortched the guts of my borlas and now I was like F*** me! After couple hundred miles and weeks they slowly came back to like they were day 1....I was and am so happy. They obviously had to dry out and return to normal.No damage.
This deal you got for whoever is interested is a win-win for both. You probably need to go GT500's. Naploeon85 can tell ya what the sound is like with set-up like you a sticking with. He traded roush or sold and got the 500's for same reasons we are talking.
So BUMP for ya man..... somebody who wants some PYPES trade is good deal here. GL man. Keep us posted on what you end up with and sound improvement