I have two PCs and a Mac. The Mac is for Photoshop, Final Cut, After Effects, Titanium Toast ... all my media software, plus it has three drives and another external drive for boucoup memory. But I would never use it to write, surf the net, do spreadsheets, etc.
It all depends what your usage will be.
My only beef is, when I make my videos, I have to convert to MPEG4, then put taht on a disk, then down;ad the MPEG4 to my PC before I can upload it to YouTube. A bit timeconsuming. But I don't like surfing the net on the Mac, so it is never online.