When I've run WMO, my engine has run a lot quieter. Not a quieter exhaust necessarily, but it cut engine "chatter" down significantly. An issue that you might deal with is "how much is too much" with regards to the thickness of your fuel. No one here complains about too thick fuel in July, the heat makes it flow pretty smoothly (assuming your filters aren't at the end of their life, and you've taken reaonable efforts to put clean fuel into your truck.
If you're starting to experiment with WMO in the winter or spring, I recommend not filling the tank completely up with oil. I've put WMO in my tank and wasn't able to get the truck revved up enough in 4th to shift into 5th. There simply wasn't enough power. But because my tank was only partially filled, I stopped at the next gas station, added 10 gallons of gasoline, and headed for the hills. That gasoline thinned out the oil so that it flowed really well (always consider your ambient temperature), and the truck ran like a top.
There's been conversations about mixing diesel with gasoline, a lot of guys have figured out that running the cheap alternative (gasoline) lowers your MPG, due to less BTU's in gasoline etc. Gasoline is useful in Oil blending applications due to it being a "somewhat safe" thinning agent.
If you decide to run a variety of fuels in your duece, remember to search for "manifold heater nozzle" and "identify this part? There is fuel leaking onto my turbo, I'm afraid I'm going to catch my truck on fire." You most likely will need to address a recalcitrant O-ring in the future.
