EPM Reports too slow

Few months ago we completed the migration of our reports from Financial Reports to Reports. Overall, they are very similar, however one common feedback we are getting from our users is that the Reports are taking longer to generate. With FR it was almost instantaneous whereas in Reports the circular loading icon is spinning for a while before the report is actually generated. Even to navigate through the Reports folders and lists seems slow.

One example of report that takes far too long is a P&L by quarter developed with two grids. It takes almost 5min to either generate the HTML or the XLS.