Flaps,
I run Spybot, Adaware, PestPatrol, ZoneAlarm and PCCillin all together with no probs. I filter popups with Webwasher (highly recommended) and spam with Mailwasher and Benign, in addition to the ZoneAlarm attachment filter.
But I'm not paranoid
And, touch wood, I haven't been infected.
Out Of Trim
GRC is not flogging firewall software, he just evaluates it and heaps well deserved scorn on pretenders, while praising the good ones. We could all do worse than take his advice, IMO, though there are some that don't like him.
Mostly those who he's exposed as shams and rip-off merchants hiding behind marketing technobabble.
AA