We migrated from R8 to R13 for Windows 7 support, and we faced some issues in the migration.
This migration was long time ago, so I don't remember the exact details, but we had some time-out issues when updating some big tables (our database is holding information of ~ 100.000 devices). We also had some issues related to a character field being changed into a date field.
So, yes, there are DB changes ;)
Falquian