I have used NAV for over 10 years, and I've been using it along with VirusBarrier X for the last 5 months. I must attest to the fact that Virus Barrier X is far faster than NAV at scanning drives (minutes vs. hours), but this is due to the fact that VBX keeps track of the files and only scanns the ones that have changed (which I don't see as a bad thing at all). I have also never had a problem with the stability of features of the app. Many grip about the daemon, but it has been flawless. In fact, it has done a better job scanning incoming email than NAV does. NetUpdate has also never caused me a problem either. The only thing NAV does better than VBX is that they update their defs weekly whereas Intego only does it each month. This app is a very fine one. Try the demo for yourself and don't be turned off by the numerous negative reviews.