I just got back from a long road trip after installation of my supertrapp muffler. I removed my 3 inch flowtech over the weekend, and installed a 5 inch od. 3 inch id. supertrapp muffler. The exhaust is basically being muffled by the converters only, as the muffler has no discs or endcap.
The flowtech had a decent sound, however it had some interior resonance at 2000 rpm. The supertrapp has a deeper tone, is a little louder, and does not seem to have as much interior resonance. I am very happy with it, bought on ebay for $36.00 shipped.
Just thought I would pass this on to you guys. I would guess the truck would probably sound very similar with no muffler at all, just letting the converters muffle the exhaust.

 

Cool! You're the first person I've seen on here that has gone with that muffler(or at least posted about it). I used to run a one on my Warrior, and have seen them listed for autos, but never seen one or heard one in person. You gonna get a sound clip for us? I would like to hear what it sounds like. Anyway, congrats on the install.