Firstly, the Insights Dashboard reporting is a fantastic improvement for Pipedrive.
One area which could however enhance this offering even more, would be the ability to use custom fields when setting up a new report.
In our particular scenario, we have a custom field on Deals called 'Business Unit' whereby deals are split across various business units within our company. It would be great to be able to use this as a filter to create a new report. (Yes we could create separate pipelines for the business units, however this has various other drawbacks for us, and is not suitable for how we work).