Setting multiple data sources across site collections was very simple. The overlay allowed us to split our sites into multiple collections for each of permissions management while still allowing us to merge and display our calendar data in a company intranet site. Review collected by and hosted on G2.com.

Setting group permissions to deal with the security issues with the app delivering multi site data was bit of a pain but not a huge issue compared to the benefits. Review collected by and hosted on G2.com.