We use nightly IRIS backups which are moved to a network share, so Test can restore the backups to an alternate application data DB via a script.  We always have 2 application DBs defined, so we can script a restore on a weekly basis so the data is readily available if a developer needs it - they simply swap from the active data DB to the alternate (the alternate is always the target of the automated restore so as not to interrupt any data depending testing which may be actively going on at the time of restore).  

We have found this to be very effective for our needs for multiple internal applications.