NOD does FAR worse than almost ALL AV systems out there and eats more system resources that most.
While it is one of the most popular it also means that malware and virus writers target and test against to make sure they can get past.
You nead to read some real world test. AVG (Nice and free and low system impact) ALWAYS places far far higher than the over priced system hog that is NOD.
Haha you kidding me, NOD was the one which didnt use many system resources. I have used it for very long and i got no viruses. AVG can be good but it takes more system resources, get ur facts straight.
McAfee and Norton are the ones that should be blamed.