I am running the MBRP on my JKU but more than merely the muffler. I added their rockcrawler version which moved the muffler further forward, almost up under the driver's floorboard. The tailpipe can then move higher up and dump over the rear axle which has added a lot of clearance at the rear departure area for off-roading. I like the sound as well, it is not tinny or high pitched but more of a deeper, throaty sound. As much as can be for a V-6 anyways. ;D
They have a great warranty also, about three years ago I had an internal spot weld come apart on the muffler which resulted in a rattle at certain RPM/loads. Once I discovered it was the muffler, I contacted MBRP and they sent me another replacement muffler at no cost, just a few questions and some information was all that was required, great customer service.
Mike.