I had that same muffler with cat bypass pipes on my 04 S. It was too much for me. As in it gave me a headache after 10 minutes. I took the muffler off the same day I put it on and put the stock one back on. This is coming from someone in their early 20s! The stock muffler with bypass pipes is a little quieter than what I would ideally want but I think it is a good compromise. Not to mention I think the stock tips look and fit a lot nicer.
Lots of people on here have the combo and like it, however. It just depends on what your preferences and expectations are. You've been warned