From what I have read, and correct me if I am wrong, the MT/R's were really designed for rocks and dust more than mud. I've read some poor reviews of the KM2's on mud, but so far, they have worked fine for my type of mud.
All in all, just like when you build a Jeep, you need to know WHAT you want to do, and then get a tire that is good for doing AS MANY of the things that you want to do as you can. For me, that means a tire that drives well on the street (either wet or dry pavement), and can handle thick, gooey mud. To me, the KM2 has fit the bill just fine.
Felipe