ITSM to HRSD migration

Client has asked to migrate catalog items from ITSM module to HRSD module as they are all HR related catalog items. I tried to read around that but couldn't find the actual benefits of moving the catalog items.

1. What are the benefits of moving them?
2. Is there any difference in the way a catalog item works in HRSD compared to ITSM?
3. What other things should be taken care while migrating the items?