I've narrowed my new machine choices down to either a JD z925 or a Ferris IS2000 or IS2500. I'll be mowing a property with quite a few long sidehills (3/8 mile), with some steep up and down as well. A lot of bumps/embedded rock in the ground around here which is why the Ferris appeals. The diesel IS2500 is attractive in terms of fuel savings and longevity. It's about a $2000 difference in price, and I think I can justify that. But I'm wondering about the extra weight of the 2500 vs the 2000, and the fact that the engine sits so much higher on the chassis. It's about 400 lbs heavier than the 2000. I'm not sure where all that extra weight is carried - is it chiefly in the engine? I'm thinking that extra weight sitting up relatively high is not going to be a friend on the sidehills or on the down slopes. Although from a traction standpoint it should help going uphill. Anyone have any experience with the IS2500 on hills?