Bob,
My comments apply to the choice between hydraulic vs. cable steering. You certainly have a biased case because you own an
unemployed cable system, so your decision of using one over the other, in this case only, is based on "Does the extra value of
hydraulics warrant the cost over no cost for the existing cable system?" Your call.

My comments about installation and buying parts refer to the design of the hydraulic system. There are several ways to make
mistakes. So it is important to do your own arithmetic verifying other's recommendations before buying parts.

On the subject of maintenance, failures are very rare if either system is installed correctly. There is simply not enough use time
in a season were wear is a cause of failure. What failures I have seen are usually corrosion issues, which resulted in a poor
choice of parts and system components.
Steve