I Have always been of the opinion that a rudder that is hung off the back of a keel is the most seaworthy, my sailing mentors & logic has told me this

.
Barring that a skeg hung rudder, then at the bottom of the list (& in the deal-breaker category for me

) is spade rudders. Even a crab pot line wrapped around the rudder could do damage?? Am I too old skool for my own good?
Being that rudder failure is probably at the top of the list as the cause of lost yachts (oh maybe nav errors are up there

), you want to get the rudder construction right, talking about ocean going yachts here.
Who has a spade rudder & is it a worry for you?