I really showed how fast a good commercial Z mower is over a regular tractor the other day. Let a friend use one of my Z's, cut his time to a third of normal. If you have a large fairly level lawn and have some bucks, a 72 inch diesel will get it done FAST. A lot of times you can buy a good used one for decent price because the market is smaller than a 60 inch. Just throwing ideas out there. I know guys say some are crazy about mowing. We mow 10 acres for one client twice a week, 4 acres are irrigated. It all gets striped in 60 inch widths with alternating diagonals weekly, with the bed edges recut twice a month and the 700 ft driveway edged each Friday. And if you don't, you're fired. Been doing it for 11 years, haven't messed up too bad yet!!!