Let me see...
Last year I was using BD IS for the first half of the year then I changed to NIS. I had A LOT of Internet issues due to BD firewall. My system was starting so slow when I was using BD, it was really bad. I know it offers great protection, they got good signatures, but there are too many bugs. Then I changed to Norton because I wanted an AV with better performance but still with good protection. This half year was better. Issues were gone, but in some test I did in a old machine that is now in the garbage, the computer running Norton IS was getting infected all the time I tested it (5 tests with only 10 Zero-Day links from Malc0de Database, spread over five months so one per month). I dont know if the quality of their signatures dropped, but it wasn't good as what it was before IMO. Some websites that test security suites like Av-test.org saw their drop too, as Norton was usually on the top, but it wasn't the case anymore. They even withdraw their product of Av-comparatives.com tests. I really didn't like it. I was like they were trying to hide something to me. So at the beginning of this year, I changed again, this time to KIS 2014. It's a bit heavier than BD IS and a lot more than NIS, but it's the one between the 3 that offers the best protection IMO, as what my test demonstrated. Also, I don't have any issues with KIS, either connection or impact problems. It did better than the two other AVs, leaving the test machine clean in my test (4 test so far with the same procedure).
So all in all, I really suggest Kaspersky Internet Security.