Unstored calculation field are useful for providing the most recent order total in systems that are not fully locked down into a transactional design.
On the other hand, unstored calculation fields can be expensive in some circumstances, for example displaying the most recent order total in a list view.
One thing that can be done with expensive fields is to place them behind one of the following…
- A “Hide object when" calculation
- A Popover
- An inactive panel (tab or slide)
…and display only as needed. This “display only as needed” technique also works well for summary fields in a list view.
There is only one correct answer on whether to use an unstored calculations field, a field set by script, or an auto-enter field…
That answer is: “it depends” 