While there are draw backs to in place families they are very useful/necessary in certain situations. There are also situations where users have used in place families in lieu of regular families and its nearly impossible to find and identify these items in the model. In either case, sorting in place families separately in the project browser would make in place families far more functional. This could be done in two ways;
1. Sort in place families separately in the project browser in the same way that groups and assemblies are sorted separately from other project elements, then sort the category of each in place family within that, or
2. Sort in place families within each family category in the project browser, similar to how the Stairs category has different subcategories within it that can be expanded.
Either of these two small tweaks would be incredibly helpful in working with in-place families within Revit and would improve their functionality.