I also seriously considered the Hydrovane. The thing that decided me against the Hydrovane were a couple of reports from owners that the unit was fine in light to moderate wind but would be overpowered in heavy air. If I have to choose I'd prefer just the opposite.
Jay, PSC 37, Kenlanu
P.S With the Cape Horn there are no lines to the wheel but rather lines belowdecks to pulleys installed on the quadrant . To use, simply pull the lines tight through a pair of jam cleats (usually on the back of the cockpit) and the unit is set. [See attached Photo] It is an elegantly engineered product as you can see from the photos of Dave Dias' instillation at
Cape Horn Steering on PS 37