Definitely get a 60 if your going to be mowing large acreage properties and better weight distribution with the wider stance for the diesel. (some guys say they weigh the same but i haven't checked into that and I doubt that a diesel would weigh as light as a gasoline.)
There is an Old Blue Chair for each and every one of us, we just have to find it.
2015 Ram 3500 6.4l hemi 4x4
BOSS 8'2" VXT
Hustler X-one 60" 3 bin bagger
Toro Proline 36" wb w/t-bar controls
Walker S14 36"
Shindaiwa T242, Echo trimmers, chainsaws, pole hedge trimmer, pole saw, hedge trimmer
Shindaiwa 633 and Echo 755