Here is my story FWIW. I installed the Eisenmann Race mufflers (it is only mufflers - no pipes) on my 4.8 not too long ago. I thought the stock exhaust sounded ok but not aggressive enough for my own taste. I ordered the setup w/o the tips as I wanted to retain the stock look. After waiting for over 10 weeks, the mufflers came in without the pipes that would make the exchange operation a "bolt-on" deal (other than for the tips). Their website clearly said that they would come with pipes for the 4.8 so my dealer contacted Eisenhaus and they said that this was a mistake because the stock pipes were already the right size to fit the mufflers and did not have to be replaced with larger ones (unlike with the 4.4). When I complained that this meant that I had to chop up my stock exhaust setup to weld on the mufflers, thereby making a return to stock or sale of my mufflers much more problematic, and that this was a lot of money for just mufflers - no matter how well made they were , they offered to return my deposit (after all these weeks of waiting) or to give me a break on the price (I think about 25% off). I took that deal although it left a bad taste in my mouth. The sound is certainly not too loud from inside the car, no droning at all, and quite an improvement over stock. I can only really clearly hear the sound difference when I open the sunroof and rear windows and really get on it and at startup in my garage. For me personally, it could be a little louder but most people tell me they really like it. I have not heard a 4.8 w/o resonators so I cannot comment on the difference. Good luck.