You won't be disappointed but you definitely won't sneak up on anyone . I had them on my '11 GT that I just traded in for a '13 GT/CS. The stock exhaust is driving me crazy, I will have something new very soon. I did the install with a friend and neither of us had done it before. Pretty easy.
It's a really easy install, only tip I have is to loosen the brace that's in the way, can't remember what it's called but if you take the bolts out on the driver side and lower it down it makes the drivers side ALOT easier... It took me about an hr to take off my gt500 and put on the roush, 45 mins of that was taking off the driver side gt500 can
I tried sneakin out today and my boss caught me lol his office right by the door so I'm gone start parkin ar the other end.of.the.lot now lol he has a vert camaro 6 banger with full exhaust and cai and it sounds like **** I told him he in for a treat lol