Both Kubota and JD are great tractors, you can't go wrong with either one.
Like someone else said you have to get the tractor that fits you and your jobs.
Dealer support plays a big role in deciding also.
I always thot I'd get a Kubota but after renting a JD 3520 eHydro for an all day lawn overseeding job, I was smitten with the machine.
The 3520 rode and handled like a dream, it just fit me ergonomically over the Kubota and it will do everything I need to do for lawn work and landscaping.
I got one a month later. At 37.5 hp and 31 pto hp its all I need and then some.
I think I would have been happy with a Kubota but I'm really pleased with my JD, it just fits me.