It depends on the nature of your lawn area. We have about 3 acres of "lawn" but there are 80+ trees in that area, a pool, two sheds, swing set, house, deck, driveway, gardens, gazebo, etc. I also maintain grass along the roads for about 4000'. We went with the commercial ZTR first and cannot imagine cutting with anything else: the speed on the straight flat, the ability to get around all the obstacles, and quality of cut are great. We are also lucky that the 3 acres were finished well and just need maintenance. It still takes 3-4 hours per week to maintain but with a tractor and finish mower it would be more.
Now we need something to assist with remainder of our property and that is where we are looking for a compact tractor to add to the ZTR. The only thing the ZTR does other than cut grass is pick up leaves with the Cyclone Rake in the fall.