Scanning Virtual Desktops
According to https://www-secure.symantec.com/connect/sites/default/files/SEP%2012.1%20Virtualization%20Best%20Practices.pdf, full scans are not necessary.
"With the increased security capabilities of SEP 12.1 Symantec recommends scheduled scans be configured as active scans instead of full scans. Active scans will scan currently running processes as well as critical system areas and result in a small amount of system activity when compared to full scans. Full scans are not required to secure the system."
So all the features like virtual exception tool, shared insight cache, vshield virtual appliance, etc are not necessary if you are not going to be doing full scans?