I just recently "switched" to a Mac
(before the ads, mind you) and I don't regret it for a second. The new mac I bought is 100mhz slower than the dell i bought 2 years ago. Do i miss those 100mhz? No. Are there other more important things that make up for it? You bet. Like the ad says, "it sends other unix [window managers] to /dev/null"
I've used PC's since I was like 3. When you get used to them they aren't so bad. The whole competitve-marketplace-for-apps-and-hardware thing makes them pretty attractive, and keeps their performance on the cutting edge. If you're into having the hardware for its own sake, get a PC. But as I'm getting older and more jaded, well, ok, FEELING older and more jaded, performance is meaning less and less.
Games and servers aside, does all that performance really get you anything? You have to wait on the HD for most things anyway, so really what's the difference between 1 and 3 GHz? If you work with graphics, then maybe you've got a bone to pick, but most other applications won't notice the difference. The last "killer-app" to seriously tax computer hardware was the web. All computers now can pretty much deal with it. Until the next big thing comes along, what do you need more mhz for? (like i said, games and servers aside)
Who cares if you can do things quickly if the things that you are doing suck? It's all about the operating system. Most of your time is spent interacting with it. Windows is aggravating and Linux is a chore. If I could buy a cheap, fast machine with mac os and a sleep function like mac's, i would. But i can't. And good thing for Apple, too. Would you buy a car with 500hp if the seats were wooden and gave you splinters? Ok, bad example maybe, cause driving fast is a lot more fun than typing fast, but you get the picture.
Everybody assumes that computers will just keep getting faster and faster and if you get left behind the wave, then you won't have any fun. Think about this: If suddenly all computer manufacturers vanished, and no more computers were made, would you be happy with the one you have NOW? For the rest of your life? I would. I couldn't say the same about any computer before this one (700mhz iBook that has yet to prove underpowered for anything important)