Well I guess technically since there are fewer moving parts one could argue that they would be less reliable. However if the prop is properly maintained, inspected and rebuilt when needed. There is no reason it would be less reliable.
I have not heard of any failures when properly maintained.
The folding prop is less effecient under power than a proper non-folding, that is a true, but this is a sailboat we are talking about not a powerboat (-:
David
