Did you know you can delete the body part in a report and produce some interesting results?
Suppose you have various levels created with their sorts and summary fields on those parts. Now you can produce a quick, fascinating report based on whatever your sort order is. Note that field parts not in your sort do not show in the report.
This method uses the summary field to display similar to number fields in the body part.
A little trial and error might produce interesting results for you.
Been doing that for years. You can even replace the body with a sub summary part such that you can expand a report to show details or collapse it to only show subtotals just be changing the sort order.