Mac vs pc: For me the difference is not at all technical. Mac computers seem to illicit an emotional response from the user/owner. Simply put-a Mac owner loves his/her computer. This is why there is a perception of a Mac Cult. Pcs get the job done, Macs get the job done artfully.
I also think this is why we have less virus problem. Microsoft is perceived as "the big global corporation" and is thus a target for every bored, disgruntled hacker out there. People seem to love to think up new ways to screw the system and Microsoft is seen as being "the system".