ReportBuilder is a great tool to have automated reports but is lacking a feature to make the automated report more powerful : make the data refresh part of a larger macro that can eventually render the final report more complete and then sky is the limit with what you can do. Obviously that feature would only apply for people refreshing their data locally (since macros will not run from the Adobe Reportbuilder servers for scheduled reports).
Example: integrate the ReportBuilder data refresh in a larger process that refreshes pivot tables, sort data, make external database connection to retrieve additional data (...). These macros can then do the little things to make a great report (e.g. only display the top bounce rates for pages that have more than xxx entries, merge natural/paid search keyword data in a single table, add external data like number of clients/accounts in database to compare with the additional clients from SiteCatalyst report)... The goal is to minimise all manual work to get the dahsboard that people need as with too many manual steps, people just either waste their time or don't do the task and have to cope with a sub-optimal report.
It is important to note that this exact same feature was available with ExcelClient (it was possible to trigger data refresh using VBA and query table refresh), so this feature request is essentially to get back a feature that was available with Excel Client...