My problem with the Polaris Sportsman 450 4x4 is that the suspension is to soft. If you throw a 100 pound corn sack on the back you cant hardly steer it. Our Big Bear does not have this poblem. Our Polaris snow mobile has less than 1000 miles on it and it has already been rebuilt. Our Yamaha sleads have been treated the exact same way and we have not had a single poblem with them.