Just took delivery of a new GR2020. It is a great machine on hills and uneven ground. It mows great and leaves a beautiful cut, as do most Kubotas. All that I have read states that the Hydrostat transmisson is a new design from the older GR's. I have had no issues with it so for. My father-in-law has an older GR2000. It is about 6 years old and he has had excellent service out of it. I feel like the GR's get a bad rap sometimes. The GR2020 has a suspension seat and rides better than the older GR's. I also have a ZG327 zero turn. It holds the hills pretty good, but there are places that I can mow with the GR2020 that I cannot mow with the ZG327.