Unfortunately I can't give much of a verdict on that as last time I fresh installed my OS it went straight on with it so I really have no comparison. My system seems to perform fine with it though but I have a reasonable spec 2.6ghz dual core with 2gb ram.

The only thing I will say is if it works, don't change it

PLUS Norton is the worst resource hog ever created, I tell everyone I know to steer clear