Personally I've used Mcaffee and found that it took up way too much CPU time to be worth bothering with, it slowed my machine down so it was practically unusable.
People who I've known that have used norton and have decided to switch have said that their new virus scanner has detected as many a fifty infected files that norton has failed to sopt.
That coupled withthe fact that you have to pay for updates will leave me using
A free anti virus scaner from www.girsoft.cmo
and a free firewall (outpost) from www.agnitum.com
I'll continue to use the free spybot search and destroy, a the program and updates are again free.
frankly Ifeel that if you've gone to the trouble of going out and buying Norton then you've wasted your time and money.