One other thing to be aware of is that graphic designers tend to prefer Macs since that's what the schools have and therefore what they've learned on.

In addition, while the Mac can read (but not necessarily write to) any Windows file system, a PC will need additional software to read the Macintosh's native file system. Therefore, when receiving files from a client, using a Mac is somewhat more straightforward.

Moving Adobe files from one platform to the other no longer presents any problem—I work on both at school without issue. Microsoft Office for the Mac platform tends to be quite sluggish. Other than that, neither platform offers much in the way of software superiority (at least in terms of publishing).