I put little stock into what equipment you use, i.e. Mac vs. PC. People are always very adamant about either platform for whatever reason. The problem is that buying a fancy looking computer wont make you a fantastic graphic designer, digital photographer, editor, or whatever. It is the amount of skill you bring with you.
You could have the most expensive and best looking race car in the world, but that will mean jack to you either if you don't have the expertise to drive it to it's potential.
Buying a Mac is not going to transform you into a well versed artist. Likewise, buying a PC doesn't mean that you should be viewed as second rate because you weren't smart enough to buy a Mac.
Like it has been said before, it is really the same stuff under the hood, the only difference is the box. Now, that being said, both boxes do have some pros and cons.
For instance, Mac has a really nice looking box lol. But it comes at a pretty penny. Also, they are able to provide better support for their computers because they are very specific on what can be put into that box and they handle all that for you, as Joce said. On the other hand, you don't have as wide of a choice with putting what you want into that box as you do with PCs because of the above.
With PCs, you have just about every choice under the sun for how you want the box to look, sound, eat, and breathe. The problem with this though, is that you can get lost in white noise and it is sometimes hard to sort through it all. If you can get through that noise though, you will usually end up on the other side with a lower price tag than a mac.
What is really important is going to be which of these aspects is the most important to you.
Honestly, my opinion: Even though I despise their marketing, I enjoy the aesthetics of Macs, I enjoy using them for my graphic work, and they have a good OS, but I would never pay that much money for one. With that same money, I can build a comparable or better PC and use the difference in money to buy camera equipment/coral/a palette of Reeses cups/etc.
I would want to invest in better hardware because I would rather spend less time sitting around waiting for things to render. I don't really care what my computer looks like. I barely ever see it under my desk :lmao:. If I had to wait around longer than I had to though, I probably would look at it more - I would spend that time giving it the evil eye.
I use a Mac and a PC and they have all the same software on both and there is only one difference between them: The shortcut keys!
Remember this mantra: "My Mac or my PC isn't what makes me a good graphic designer, my skills do."
For what it's worth, if you REALLY want a mac, but dont want to spend all that money, look into a hackintosh - regular (compatible) pc hardware and Mac Snow Leopard. The perk is that you can then put Windows back onto it and dual boot. This will be my next project, after I am finished sinking all of my money into my tank... I will let you know how it goes when I decide to break my tank down. lol.