There is a considerable difference between Norton 2002 and 2003 regarding functionality. However the difference between 2003 and 2004 seems to be slim and 2004 is a resource hog. Theoritically, a virus scanner is as good as the capability of it's virus definitions, at least when comparing difference releases of the same brand.
There were few discussions regarding similar topics before. Maybe a search on the topic would help you further.
HTH / Cheers.
Stone walls do not a prison make,
Nor iron bars a cage;
Minds innocent and quiet take
That for an hermitage;
If I have freedom in my love,
And in my soul am free,
Angels alone that soar above
Enjoy such liberty. - Richard Lovelace