At this point, I think CSV export would be most useful for us.
I’m regularly asked “who downloaded these products in the last X days/weeks/months?” For this most basic question, I’d need to be able to specify one or more products and the desired timeframe. The results need to include the user (account, or IP address if not logged in) and dates. We’d also like to be able to lookup a user or ip address (or ip range, or domain) and see the download history for a given time period. These are current needs.
I won’t be surprised if I’m asked to plot downloads by country (based on IP address) for each product over time.
One thing to note though, is that displaying the data in the GUI is of limited usefulness if the output is paginated. Right now I have to copy/paste text from dozens or hundreds of pages, and it’s a real problem. Additional options in the GUI would be nice, but a CSV export would let us manipulate the data however we need, and without any copy/paste.