What do you think about letting the users to have multiple levels of Row groupings in reports. I understand that the users could use the filters to drill down into one single category. But, letting the users to have multiple levels of row grouping will allow the users to read the data points easily and compare it with other records.
If I am building a report on Survey responses, I would be like to have the report grouped by Company, then by Respondents, then by the Survey and then by the Response Date. This will allow the users to read the data effectively.