I just put one of these on my 2012 Ram Sport and thought I'd provide a review and a couple pictures, so people can see what they are like installed and my opinion of it.
I am actually suprpised there is very little information on these in the forum. My truck has the mufflex 18" system on it. I loved the sound, had no problems with it in the city, but the drone on the highway really bothered me. I do a bit of long distance towing. The truck under load at anything under 1900rpm was annoying. I am used to Corsa exhausts that can be very loud, but have NO drone. That is not the case with Mufflex.
My first impression is: this is how all mufflex systems should come. They should find a way to add this type of tuned pipe inside the muffler. Initial startup after the install was night and day. The truck is so much quieter inside. Still all the volume out the back. Idle and driving around town is almost like having a stock exhaust back on the truck (at least until you get on the go pedal hard). I'm loving it.
It does not completely eliminate drone. I still get noticeable drone from around 1600rpm to 1800rpm on the highway. However, it is much less than before. And everything outside that range is now almost stock-like quiet, unless you kick it down. When you do that, it is not drone you hear, it is the exhaust noise from the back of the truck.
The worst drone you can get (lugging the truck in gear just up to the point of kick down) is about the same volume as it used to be in this range when the truck was just cruising and not under load.
To sum it up: Much quieter in the cabin at idle and driving around town. On the highway, it does not completely eliminate drone, but does quite noticeably suppress the drone. I should have taken dB readings before and after. Sorry I did not think of it. Anyone sensitive to drone, but still wanting a louder exhaust, should definitely get the drone suppression pipe with a mufflex system. In fact, with the drone suppression pipe, I would now be willing to buy the 14" muffler.
I feel it is well worth the money, as I was prepared to pull the mufflex system off and put something else on. This now hits the sweet spot between an exhaust with a performance sound I can hear and acceptable drone without having to buy a different system.
Here are a couple installed pics: