Brent,
I have an Apple Mac Mini, running OS-X 10.6.3 and also a Compaq running Windows 7. Both computers are new since Nov 09.
The Mac only gets one or two (if that many) updates or security patches from Apple per month. The Windows 7 machine gets the usual 5 to 10 patches weekly.
I am just a computer user, but my understanding is that Mac computers use unix as the operating core of the computer, and that core can not be changed without the operator allowing the change by entering the administrator password.
If I understand Windows correctly, any .exe file can change the core of the machine, and do not require the admin password to do so.
I do not have any anti-virus software on the Mac. I have not had any problems.
I have AGV free anti-virus on the W 7 machine, and so far I have not had any problems, but the W 7 is only used for navigation and only goes online to access Rose Point for Coastal Explorer updates and to get the W 7 patches.
The Mac can pass viruses thru the machine by getting an infected email, and then forwarding that email to others, but the virus does no harm to the Mac.
Anyone wanting to learn more about Mac computers can check this link to a user forum.
http://www.mac-forums.com/forums/switcher-hangout/
Conclusion, I love my Mac! When Coastal Explorer releases a Mac version, I will get rid of all my PC pain-in-the-A machines.