Unnecessary downloads and inefficiency. When you run a report, often you just need to see the results or be able to view them quickly without having to download. This is especially true when needed to look at information on inactive matters or users (where, in order to just see them in search results, you have to make them active to be available in the dropdown choices). Being able to view the results would also allow you to see adjustments that you need to make in the way you ran the report to get the results you're looking for. Also, given some of the sensitive information generated in the reports, keeping downloads cleaned out and recycle bins emptied becomes time consuming.
It would be useful to have the reports run to a display window/view of the results with the option to download if needed.
How often would you use this request?
With almost every report that I run.