Your satisfaction with product and support?

My company is considering purchasing: Symantec Endpoint Protection (SEP) and Data Center Security (DCS). Can you help?... 1) How is support?  Is Symantec responsive to issues? Do they take ownership of problems? 2) Does the product do a good job of protecting against advanced persistent threats? 3) Has the product helped you identify security issues in your system? 4) Are whitelisting features easy to manage?  Thank you in advance for any feedback!  L