You can check the system log under the monitors tab. Set the log type to System and log content to Client Activity and this should show which clients are downloading full sets:
This article should provide guidance on filtering:
SEPM 12.1 - Advanced Settings filter options for Client Activity logs
https://www-secure.symantec.com/connect/articles/sepm-121-advanced-settings-filter-options-client-activity-logs
Set the event source to sylink: