I've had the KO2s and they not only sling, but they take a couple of miles to clean out. I next had the Nitto Ridge Grapplers and they did not sling much and cleaned out almost instantly. My last tires are the Cooper AT3 XLTs. They do not sling bad, but take more to clean out than the Nittos. All were LT tires.
The last set of Ridge Grapplers vibrated like hell, and after the second set did the same they switched them out for the AT3s. I had the same shop put the Ridge Grapplers on my 15' Ram and wanted the same on my 17' Ram. The Nitto Ridge Grapplers have a rough ride even when balanced! I am happy with the smoother ride of the AT3s. The AT3s have a 2 ply sidewall vs the 3 ply sidewall of the Ridge Grapplers. They both have the aggressive looking sidewalls. I noticed slightly less Winter traction with the AT3s, but they get me up my driveway hill in 2 wheel. The factory Firestones would not!
I had wanted to switch from the Nittos to the Toyos, but the dealer said that they were the essentially the same company as Nitto and could not order me the Toyos cause they sell the Nittos.
Gas mileage wise I can not tell you the AT3s would be much better than the Nittos... It is not about gas mileage for me. I drive mainly highway, but go off road in camping season so I need a tire that can handle that too!