Wow, 9:0 in favor of R1's and no one has even mentioned the tired old argument that R4's have greater puncture resistance for woods work. See if you can talk those confused salesman into letting you try out some R4's and R1's in the mud. I will be #10 for the R1's. R4's are best only for the industrial uses for which they were designed. If you can afford seperate machines with R1's for off the lawn and turfs for on the lawn, you are far ahead of the poor folks who are stuck with the R4's and must suffer some lawn damage and a near complete traction loss in mud or snow.