Well, depends on your location.. Rain, or snow?
My experience, with exhaust.. I live in the Northeast, so we have salt, harsh weather, on the roads. The salt used in snow/ice, is the worst thing possible for the truck... I choose to run the exhaust, tight right around the hitch, because otherwise corrosion might occur, from the tires spitting up chit off the road... Also, I kind of like how it sounds... What about pulling a Roush, or Stillen maneuver, and running it out in front of the rear tire well? That might look interesting, flush with the rocker panels. Or, even more interesting, how about the Mclaren SLR application, and multi pipe it right out the front fender (practically..)... I have true dual Flowmaster Stage 2's, as my cousin told me 3's get obnoxious... I am thoroughly pleased with my 2's...
Sean