A new transmission on a tractor with eight hours - a very uncommon situation. As such, it really doesn't reflect on the reliability of HST vs geared.
My dealer - third generation of the family that started the dealership in the 1920's - discussed transmissions with me. In CUTs sold to homeowners, they are over 90% HST. Every tractor under 45 hp he had in stock (three locations) was HST. As we discussed my intended use in steep mountainous wooded terrain, he said I was in the 10% that would be better served with gears if I drive properly, HST if I drive like most homeowners. Either transmission would require repair, sooner or later, and that would require splitting the tractor. Typically, the geared would be a clutch and the HST would be a pump rebuild/replace. Labor would be slightly less on the geared, parts would typically be considerably less. Frequency would depend on my ability to avoid riding the clutch and using the proper gear selection. He also mentioned how simplicity factors into reliability - there is virtually nothing electrically-operated inside the geared transmission. Since he had to locate me the particular geared model I bought, while he had several comparable HST versions on hand, I believe he truly believed what he was telling me.
As far as failure rates reported on the forums, that's statistically hogwash. Most HSTs are newer than most gear drives. For example: You'll find lots more clutch changes on Ford 8Ns than HST repairs on the same model. Thirty years from now, there will be a lot more HST failures than geared failures on 2018 models - since there are so many more HSTs sold now.
All that said, I'm not anti-HST at all. I have a friend who recently purchased horse property. His slopes are gentle, he'll do maintenance on a ring, and he (and his wife) will be doing a lot of loader work. If he buys new, he should get a HST.
