I recently made the switch from a subcompact with a belly mower to a zero turn...best decision I ever made.
I mow just over 4 acres, and previously did the mowing with a Massey Ferguson GC2300 w/ a 60" deck. I hated how the deck dispersed the clippings (it didn't), and unless the blades were brand new the deck didn't mow cleanly in heavy grass.
I traded the tractor towards a John Deere Z950A zero turn with a 72" deck. The John Deere is an absolute beast, it blows the grass about 12' out of the deck, and doesn't care if it is wet, tall, or very thick. I have no problem mowing the ditches, and the quality of the cut is outstanding. It "cut" my mowing time in half, and I have less trim than before.