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.
2006 GMC Sierra 2500hd crew cab
BOSS 8'2" Power V
Hustler X-one 60"
Toro Proline 36" wb w/t-bar controls
JS46 22" walk-behind (wouldn't recommend)
Shindaiwa T254, Echo trimmers, chainsaws, pole hedge trimmer, pole saw, hedge trimmer
Shindaiwa 633 and Husqvarna 130BT blower