this should help
the URL below shows the comparision and benefit of SEP 14 over SEP 12.
https://www.symantec.com/content/dam/symantec/docs/other-resources/endpoint-protection-14-vs-12-comparison-chart-en.pdf
Also refer this KB article
whats new in SEP 14
https://support.symantec.com/en_US/article.HOWTO125362.html