I just put a set of 305/60R18 Nitto Terra Grapplers on my truck and I love them so far. Haven't really had them on anything other than the highway (yet) but they ride a lot quieter and 1000% smoother than my KM2s did. Unfortunately the 18" wheel size and the aspect ratio of the tire I went with meant paying out the @$$ for them. But hey, ya gotta pay to play. Right?
-Eric