Do you have any steep banks you mow ?
If so a cab is really top heavy & can get you in trouble

This is my problem plus a cab won’t fit under my commercial poultry house equipment inside 500’ long.
Everyone’s application is different.
You can always cut all of your low hanging tree limbs to accommodate a cab tractor.
Another issue is a cab adds more weight & AC robs HP & really noticeable on Hills.
So as the other poster mentioned : I’d definitely step UP to the 4066M (R isn’t necessary : but slightly used low hour) even IF you think you don’t need it.
Trust me I’ve made numerous tractor upgrades in 30yrs from 48 66 85 93 101 & 115HP LOL
Fluid Filled tires which all 4 are mandatory for my applications: adds so much traction, stability on steep banks & rides way better on rough ground But Robs power big time pulling hills & mowing thick grass.
It’s just like building a shop : ALWAYS go Bigger than you need or can afford because you’ll really appreciate it down the road & saving $$ in the long run.