after using hydrostatic tractors and six gear collar shift tractors i genuinely do not understand the appeal of hydrostatic drive. they say it has superior torque at low speeds but honestly i really doubt the hydrostatic kubota we have at work could pull a plough or disc tiller nearly as well as the six gear kubota i used as a farmhand in ye olde. i suppose if you're running hydraulic systems to begin with for the attachments it's a logical next step to have the drive function off the same system, but a manually geared transmission can have the ratio adjusted to increase torque whereas the hydrostatic is fixed which i consider a serious disadvantage. also seems more prone to failure but i'm not certain about that