In my experience, it has been a little difficult to learn how to use (and remember to use) the different catalogs in PastPerfect. My predecessors used Objects for all kinds of collection materials. Our Archivist and I have found that the Archives and Photo catalogs are very useful as they contain fields specific to describing and organizing archival collections and photos. Our basic criteria is that if it is a single document of some kind or a collection of Archival material the record resides in Archives, a photograph record resides in Photos and books in our reference library has thier record in Library catalog. For most records, we don’t fully utilize all the fields available.
All 3-dimensional items records reside in Objects. There are some exceptions of course. Now that we are used to how the search feature works, we have few problems using and searching the different catalogs.