New mower? I currently have a 52 Toro Z100 w/ 19 hp Kaw. I am contemplating purchasing a 60 Z (brand to be determined, but top candidates are Exmark, Chopper, or Toro). My reason for looking at the new mower is that I am about maxed out as far as how much work I can get done with current mower (or as much as I can get done in the hours I want to work). In looking at the Exmark productivity chart, I see the following productivity numbers: 6mph 52 60 Acres per hour 2.52 vs 2.91 7mph 2.94 vs 3.40 8mph 3.36 vs 3.88 By going up from a 52 to a 60 will I gain more than the charts indicate? I assume that the larger machine will be able to provide a quality cut at a faster speed due to larger tires, better ride, etc, so that property I am cutting currently at perhaps 6mph I might be able to cut at 7 or 8 mph with the larger machine and gain both speed and width of cut. (Also, top rated speed on current mower is 8.1 mph). Is that a valid assumption? Also, how many of you find that the 60 is too big? I dont think I really have any properties that the 52 will fit on that a 60 wont. Im not looking for a brand or cost comparison, just theories on the benefits or drawbacks of going up to a larger sized mower. Thoughts?