The new Journal Entry report type is fantastic. I've used it for creating dashboards which record commonly referred-to and updated custom form fields. I've also created dashboards for admin/group leads to do some sleuthing when data was changed in order to increase transparency.
That said, the main problem is that you can't export the thing. I understand that, if you don't filter it out, you'll get an unreasonable list of results. That said, if used in a layout template on the Project/Task/Issue pages, the need to export is self-evident.
Ideally, we should have the ability to either turn exporting ON or OFF, depending upon the type of report and where it's used.