I grew up on Solaris (Unix). Then spent many years in corporate America on PCs. Then spent just as many years doing the dual windows/Linux thing.
Then I got my first Mac about 2 years ago. I have not used a PC since. Nor any of my old Linux distros.
You get everything. A unix based OS. Command line power. Very stable and easy GUI if you want. All dev stuff works on macs. Easy installs with dmg files. Or just use yum or whatever you prefer to install direct over the wire. Photoshop runs amazing on it. Gimp as well.
I've really been impressed with the stability and ease of use. The track pad on the laptops is the best I've ever used.
I've never been a Mac fan. Then 2 years ago I got one off craigslist for $800. Can't see myself ever going back.
For any die hard lamp devs, if you find yourself deciding between a Mac and anything else. Consider trying the Mac!