You are correct in that the reports for Devices and Users require filters. If you desire a list of either, you will have to query the "psbprint" database directly. Your source tables would be Devices and Users. You may also find more benefit in querying the DevicesView view, as this has more information than the source Devices table.
Thanks for the answer, I was afraid it would come to that. Since we currently don't have access to the server that contains the DB, nor to the DB itself, it's difficult to query the database directly, without having to go through a time-consuming approval process at the customer's. Do you see any other (easier) possibility to get this kind of information? Any tools or Blueprint add-ins perhaps that allows one to get this kind of basic info?