I prefer the big abyss of polarized differences because of the interrelation(the real only person of a relationship), can create more energy flows between people. It's a risk factor but if both people have a strong ontological(self) security to keep both personalities intact there is a richer relationship.
But in the eye of an observer is a waste of time discussing the qualities of each partner that we can't see, so I stick to watching the resulting interrelated persona, that is observable.
If you want to change a relationship, never try to change any qualities of the peers, but try to see and discuss what's wrong in the middle, otherwise you will finish playing the Guilt game of the jewish-christian(or puritane) culture and the relation is already lost.