I've been thinking a lot about this and have also discussed with a friend. He's an MIT graduate and has been the Director of the IT Dept. for the complete University of Maine system for 30 years. His comments were:
1. For the average user security is a 50/50 toss up between a Linux Distro like Ubuntu with just a Firewall & a fully protected Widows system. The difference is that with the Windows system you'll know if you have issues as all your real time and off line scanners will warn you. With Ubuntu your only real assurance is what others have said, me included." you'll be safe" Their intrusion detection products are either SO COMPLEX or they don't work.

I Installed an intrusion detection program yesterday after this conversation here. Wireshark. Seemed really nice. Clicked on the icons to view available network connections and it showed none. Found out that the program has to be run with ROOT priviledges. This is TOTALLY against the whole Linux mantra. I said OK I'll try it. So I sudo wireshark and I get a pig popup telling me of the dangers of running this program as ROOT with a direction to their site that further explains to never run this program as ROOT but it's the only way it'll run. It was fun a geeky for awhile but I have no desire to be a programmer. I'll leave the duel boot for awhile but I'm gonna go back, in fact I'm on it, to Windows for awhile.

John
ESI Gigaport HD+
Lenovo Turion II /4 Gig Ram/ Win7x64 be
15.6" Monitor
"The only Band is a Real Band"
www.wintertexaninfo.com/BANDS/JohnnyD.php