As you know, if you read this blog, I had promised a set of posts on what constitutes good reasons to opt for the very expensive route of having your divorce resolved by a judge after a trial, rather than controlling the outcome by settlement. (I happen to be a control freak who loves trying cases so I have a slightly schizophrenic view of this.)
A lot of trials happen because of valuation issues. When one or the other of you has an ownership interest in a closely held company, a significant professional practice, or in major investment real estate, those items have to be valued before you and your soon to be ex can reach agreement on the division of assets, and sometimes before the support can be finally set. This is an expensive process to start, as valuation experts do not come cheap. The cost can run in the tens of thousands of dollars, particularly when the business is complex.
Generally speaking I do not often agree on utilizing a joint expert, I find that if one side disagrees after the joint expert has given her opinion of value, you have a guaranteed trial. If both of you have valuation experts and if the experts are able to talk and hear each other out, often the differences in value can be compromised. But if the difference in values is huge, and that happens fairly often, then the amount of money at stake will generally drive the matter to trial.
In the end, the choice of whether or not to go to trial over valuation differences is an economic decision, the cost of trial and the uncertainty of outcome balanced against the differential between the values.