Ok looking at the specs on the two respective sites they look very similar in specs.
Kubota 6680 lbs. farmall 6280 lbs.
3 pt lift. Kubota 7275 (optional). Farmall 4630 ( no optional increase)
Hyd flow. Kubota 17.0 gpm. Farmall 16.9 gpm
Both have one rear remote standard
Both have an optional 12x12 hydraulic shuttle transmission
Kubota 230 cu in Vs farmall 195 cu in. Not sure this is an advantage one way or another.
Wheelbase is within an inch between them.
Standard tire size is the same.
Take the time to go operate both of them as "on paper" they look very similar.