I'm looking at a much needed computer upgrade and have always used PC's. This machine will be running Lightroom & Photoshop only.
I'm not going to try and convince you, but most graphic designers artists whatever you want to call them. The last I checked and spoken to many, a good percentage use Mac's.
1: The way how the UI works, its more fluid than Windows. (I just love how I interact with the OS X UI, keyboard shortcuts, Quicksilver and so on)
2: Colour Management. (I and they need good accuracy)
3: Stability and reliability.
I use to be a PC user. I can't stand Windows anymore. Everything bugs me to no end with Windows, and I have been a Windows user longer than a OS X user. I find OS X like second nature to my work activities.
However. When I decided to get my first Mac. I never asked on any forum etc or other people. I done my own research. The goods the bad's and so on. I also did not go to an Apple store to try out a Mac before I decided to purchase. I took a big risk and bought from the Apple online store, and it was a big risk that paid off from a good year or so of research.
I'm not trying to sound harsh towards you, I'm just explaining how I got into Apple computers.
Now I see PC's as your general motors. Sure you'll get them cheap and your average run of the mill etc, but the features and extras all the good things from Apple's OS X operating system is like going and buying a Rolls Royce/Mercedes Sport/Jaguar.
I'm sure you've heard the saying "you get what you pay for".
You can't get 100% perfection. After all its made by humans, but its 10 times better than the cheaper options, and to this day I'll never touch a PC again.
I still have some old-ish PC's (and they are not beige boxes, 1 is custom built by myself, just over a year old the other is 3 years old, custom built again) but they hardly ever get switched on as Windows is satan to me.
Windows world: Get new drivers = pain, bugs in the drivers = pain, Windows peculiarities = pain. Windows pain in the ass multi tasking capabilities = pain.
XP or Vista 32bit can't run more than 2 - 3GB, so I'd have to get a 64bit Windows OS, more money and the annoying amount of different versions of Windows. And then theres upgrading PC hardware because your piece of software needs faster hardware, but I find Mac hardware lasts longer and can do my tasks better and last longer than what a Windows machine will require.
Oh and 64bit Windows isn't all rosy in the 64bit driver department. If you have problems with it, 32bit driver versions get priority first.
I could go on forever with the pain I've had with Windows for the past decade. I do however have always solved my problems with Windows, but I had spent so much time fixing the damn thing than getting anything done!
It wasn't also that problems couldn't be fixed on my end because it was problems from 3rd party drivers from NVIDIA or ATI amongst many others that was well known. You either had to suffer it, get on with it and let it annoy you. Or they denied it, then the users problems eventually got exposed and rectified. Sometimes I've had driver tickets open with ATI for 7 - 10 months before it got fixed. Some people over a year. To me thats not acceptable.
At the end of the day, its what works for you and simply Windows computers just don't work for me (ie, not get along with the way I interact with the machine).