I have a MagnaFlow X-Pipe with cats and a MagnaFlow Magna Pack race series cat-back... it is so ridiculous how loud it is. I love it! I would only recommend this however if you have the power to back it up. It is about 7 decibels over the legal limit in California which is 95 so it gets a lot of attention. The performance is amazing as well. I would recmmend the race series to anyone.
Installed the MagnaFlow Cat Back today and I am happy. Very quite and deep. No drone at all. If you did not know Cobra's you would think it sounded stock.