Just (today) updated from 2011 to 2013 without issue.
Looking back at my history of (Symantec / Norton) products, was surprised to see
such a long list dating back 10 years or more = Time flies.
Probably would go back further although not recorded (eek),
Anyway keep up the great work, and thanks to all involved for your dedication!
As I have never had an issue = So far.
Systems = always self builds = lol