My typical reporting process is:
Create a topic with specified fields from a database view
Use the topic to create an ad hoc view then the report
Issue: Customer later comes and says they want a new field available (or a masking definition changed - e.g., more decimal places) for an ad hoc view.
I add the field/update to the topic but since the query is actually hard coded in the ad hoc view (not just a reference back to the topic), I now have to redo the ad hoc view as well - the topic change is not reflected or refreshed in the view.
If the ad hoc view just referenced the topic, I could make a simple change to add a field without having to redo the entire view as well (with filters, and sorts, etc.).
This situation occurs often where a specific customer wants something added due to processing needs. Would like an easier way to update queries/topics without having to redo the entire ad hoc view/report/