I think the key to any autopilot, irrespective of whether its hydraulic or electric, is to have it permanently mounted below deck. Those tiller mounted rams seem to be only useful and reliable when either motoring or in light winds with minimal seaway.
I've been impressed with Raymarines below deck electric ram thats bolted to the rudder stock and course computer with the above deck control head. Its been very reliable and upgrade-able as new technology arrives. I'm not sure of the cost, but I think the whole system is worth about $5-6k? and has some neat functionality (when networked with