Here's my take (having owned both HST tractors and gear tractors.
It all depends on what you plan on doing with it, now and in the future. HST is nice for loader work and stuff around the homestead, not so good for more intensive stuff like running a chopper or ground engagement of any kind.
With a dry clutch unit, expect a life expectancy of around 2500 hours average. May be lots more, may be lots less depending on how you treat the clutch but, at some point it will require replacement and that entails splitting the tractor and expense nd unless yiu are extremely handy and have the tools and place to do it, it will be a dealer thing.
Having said all that, that is why both my machines are hydraulic shuttle. All the advantages of a gear transmission (12 and 12) without the parasitic loss of an HST and without a dry clutch. The clutch pack runs in oil nd is multi plate and engagement is hydraulically controlled.
Yes they have a ckutch pedal but that pedal is connected to a hydraulic valve that modulates the pack so no dry clutch issues.
I would not have anything else. Instant forward to reverse with modulated direction changes.
I liked my HST tractors but the parasitic power loss and the excess heat I don't care for.
I have no idea where Kubota offers the hydraulic shuttle option in their lineup but in my humble opinion, it's the way to go. In lieu of that a HST but expect power loss and heat. It is, after all, an automatic transmission of sorts.