All of u just counted one aspect in ur judgement. But observe that with Norton AV, ur system becomes too slow even if that is high end P-4, McAfee cannot repair or even catch some viruses, and Kerspsky is a nice but not high end. Now come to AVG Professional (latest version 7.247), but i have 7.245, it catches all the viruses(100% only antivirus ranking), and the system uses is just 0.2-0.4 for onfly file scanning and 8% for normal virus scanning. isn't this is the nice one. no antivirus comes inbetween when u use it just for once. Go and get it... and try