Unless you plan on working on hard pack and will be using your tractor for plotting, etc. I'd personally go with the ag tires. We have a 55hp kubota 4x4 with R4 tires and a 48 hp john deere 2wd with R1 tires. The john deere pulls a disk better than the kubota in 2wd. Also the john deere will go places only the kubota can go in 4wd. I also noticed the kubota's tires have a hard time shedding the type of mud we have. Once the tread gets packed it's over. If these tires ever wear out we will be replacing them with ag tires no doubt.