I have never had a mac computer but one of the main reasons I have heard to own one is that they are much less susceptible to viruses. Whether that's because they are better defended by a MAC Antivirus or because they are used less I'm not sure.
Generally the virus makers will target the more ubiquitous systems unless there is some obvious and easily exploitable flaw in a lesser used one. Someday maybe I'll get one but at this point I'm still a pc guy.
