It was interested to read in this article by Sbarra et al (2005) http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2964496/
that “compared with parents who litigated their custody disputes, participants who mediated their settlements reported significantly more feelings of longing for their ex-partner and feeling like the separation was a mistake at the 12-year follow-up.” The authors give various reasons for this. One is the role of mediation in fostering good relationships between the couple, and the fact that mediation enables couples to work together, and as a result they may wonder why they ever separated. On the other hand, they suggest that litigation results in such bad feelings between the couple that they are more able to accept the separation.
If there are no children it is easy for both parties to “airbrush” one another out of their lives, but when there are children, it is important that they can remain on good terms as there are so many occasions they will be meeting up, such as Christenings, weddings and funerals.