One of the downsides to a hydroboost is the complete loss of power assist if the engine stalls and won't restart. Those master and wheel cylinders that have undergone multiple rebuilds can be made better than new with stainless steel sleeves that will outlive our grandchildren.
Jerry
Similar to adding a vacuum reservoir for a hydrovac, you could add a hydraulic accumulator to the pressure side of the hydraulic lines to give you some stored pressure if the engine quits. It would be rather costly though.
