No, I don't think so. I think it's right that people tend to get along with their duals, and maybe it's good to interact with them occasionally, but @Adam Strange is the only person I can think of here who seems to think duality is somehow necessary for a healthy relationship or for a healthy approach to life in general.

From what I've seen of dual couples, I think one or both partners tend to fall into a kind of psychic laziness approaching acedia. They seem fairly stable on a certain level, though. Less likely to break up than average, I'd guess.