My property is like a pool table except for ditches. And when I'm mowing roadsides with the Kubota there are several areas with enough slope, and wet areas just to the right, where after rains the tractor will start to slide to the right, which is very disconcerting (sure makes the eyes go wide open...) so I tried mowing in 4wd. End of problem, much more secure feeling. Just a matter of grip.
I was always told to keep the tractor out of 4wd unless needed due to fuel consumption and wear/tear. Now I've also read a zillion posts here saying that's nuts, the tractor is designed to run all day long in 4wd, obviously not on paved/concrete surfaces.
So I learned something here and use 4wd now for a lot more than loader work. In my case, better to be safe than sorry. Plus I changed out the front hydraulic fluid with Kubota's "better" fluid at 300 hours and it all works very nicely.
I hope one of you tells me I'm crazy but I don't see any 4wd indicator on my Kubota's dash. I wish it had one.