The entirity of my experience with Norton was 3-4 years ago, and it was ****. My parents were getting free AVG through their ISP, and the company switched to Norton from McAfee (score x2).
The program was worse than any virus I've ever seen. The system slowed to a crawl, even when it wasn't scanning. Start-up increased to taking several minutes. And this was for all of their machines--including their brand new laptop that had never had McAfee on it, so it can't have been from a bad interaction with a remnant of that program.
I have no clue what the protection is like, because at this point I would choose zero protection with caution over Norton. Maybe they just had a really bad experience. Maybe that years' suite was uncharacteristically awful. But the fact that it had the same effect on their old systems as the brand new one makes me think it wasn't a program interaction.