Eddie ran some toyos on Moby before the mud graps and now the kspecs. May want to check those out as the toyos mt are pretty solid rubber for DD. The Kspecs only came out recently, so not sure if you're going to get long term mileage just yet.
I think the K-spec is "king of the hammers" and is a similar compound to that used for racing, so I am going to go out on a limb and say its softer, and the on road tread life is not going to be as good as a normal compound. But I could be wrong.
So Yokohama geolander's are out of the picture?