I mow about three acres, part of it is pretty flat and the rest is hill side. For about the last 20 years I've mowed with a little International tractor with a belly mower. Early last spring I found a good deal on an older Gravely 260Z, 60" cut with a 27hp Kohler engine. The zero turn cut my mowing time in half, it does a great job but is a lot louder than my tractor and rides a lot rougher even with the suspension seat. On a hill side you have to slow down and pay attention when making turns. It's strange but the drier it is, like late July through early September the more the mower tries to slide when making a turn. A couple friends of mine have similar mowers and claim that the chevron tires really helped making turns

If I were buying new I'd probably buy a Gravely Pro Turn 260. Whatever you buy I'd get a carbureted Kawasaki or a Yamaha, also make sure it has a fabricated deck, not stamped. The fuel injected mowers have to many electronics to suit me, KISS.