My thought is that it depends on where you're using it.
If it's at work, go with what others are using-just to support the idea of standardization.
If it's at home, you might be better off with the avg product.
I have avg running at home on one computer that will not run the McAfee v5 I bought for it. I have McAfee v5 on another system.
I used McAfee v5 on my computer at work. It worked fine. I tried an upgrade to v6 and had some problems-I can't remember if it was the install or in feeling like the computer was running a lot slower-I uninstalled it, went back to v5 until the company switched everbody to Norton. I have been afraid to try McAfee v6 or 7 on anything else.