I am getting the tractor from Hurst Kubota in Marietta,Oh. My 2150 came from there and they have always been great to deal with. The reason for the R-1 tires is that I have some hills to deal with and I use my box scraper and rear blade quite alot and do a fair amount of work with my bush hog, as well as some tilling, so the extra traction is helpful.My mowing is pretty wide open so I dont have to worry about turning around obstacles and tearing up the grass. I have two buddies with the R-4's and they say that one revolution in soft ground and they have one big slick tire that wont clean out unless they run in road gear, then you know what kind of a mess that is! They also mention that they will slide on damp grass, so I will stay with the R-1's as I have had very good luck with them on my 2150. Thanks, Bret