We have 3 transats under our belt with our wonderful hydrovane. One thing I wish they had advised us to do on first fitting & should have considered for myself (but the rush was on) was to put plenty of Duralac (or similar anti corrosion gunk) everywhere a stainless bolt/washer was in contact with the cast aluminium. It did not take long for nasty corrosion products to arrive!
Otherwise in my opinion the best self steering there is!
One last thought - a good idea is to make up a rig to use a simple simple electric autohelm so that full use of unit can be made (eg if you have to motor) should you lose main rudder.