As I understand it, Norton Internet Security and Norton 360 are being discontinued but I don't know if this has happened yet. However, if renewal time has arrived and if wanting to continue using Norton, I'd say it might be best to go for the new product now (Norton Security 2015). All Norton's layers of security have been rolled into one program. The revamped program is getting some positive reports by those who major on trying out security products over on Wilders Security Forums.
I used Norton Internet Security from 2009 to 2012 and found it OK. Not heavy on the system at all. I recently tried the latest product and if the figures in Task Manager are anything to go by, this too is light. I haven't kept it though. The reason I don't run a Norton security suite now is because it puts toolbars in browsers and has a password manager that I wouldn't use. These days I prefer a product that doesn't include the added parts/functions that security suites have.