I have had no problems whatsoever with Norton on my BT internet account, with full scanning taking place automatically, or when I request it on my PC.
It has occasional flagged up a warning of a suspect internet / company contact, which it has stopped. 
As a free service as part of my BT package it has saved me a good amount of money over the years I have had it. 
It is far to resource hungry and tends to impede daily use of the PC
What does that mean?? Impede daily use?? I have never noticed any difficulties. Surely, if Norton was such a challenge, BT would not risk promoting it. Until now, I have not heard of anyone questioning its worth.
TB; I am not a "Daft purchaser" , but for me FREE Norton via BT is something I know is there, better than it not being. It does flash up warnings as necessary, with "peace of mind" for someone like me who really goes along with IT because, in this day and age, we have little choice. Unless you are a hermit, leaving in a cave, I, at 73, just likes that little bit of protection from nasties whilst having to use a PC.
