I have the straight pipe on my truck and really like it. At 65 mph empty it sounds stock to me, it all depends on how much throttle you give it . I would not want one if I was pulling a heavy load long distances though. You can drive it quietly if you want, but under a heavy foot it is really loud. I notice people trying to get away from me when I'm driving in the left lane and they're in the right lane

 

Just last weekend i replaced my MBRP (DPPI) exhaust system muffler with a piece of 4in ss pipe from them, I must say i am glad that i did that. I would say it is louder then it is with the muffler even though the muffler is pretty loud, I believe that you can hear the turbo whine from the exhaust pipe much better when it is straight piped then you can with the muffler on. I would straight pipe it if i were you because i started off with the muffler and then i heard some dodges that were straight pipe and then i said i got to have that tone and whine and changed it right off

 

When you are comparing sound levels with the straight pipe, remember, some have cats and some don't. They count as noise reduction devices. There's also the whole SO vs HO. Then factor in who is telling the story. I hardly ever have any windows down at all. For me, the straight pipe is not bad. No where near what my 360 gas with flowmaster was. I have no problem blocking out the tone with the radio set at a level you can still talk over without raising your voice. SO with a cat and Bully Dog programmer.