I became a Mac user about four months ago.
$700 on eBay got me a 15-inch widescreen 400Mhz G4 PowerBook with an 80GB harddrive. I've since swapped out the include 256MB RAM for 512MB from my 2GHz P4 laptop.
* It has trouble playing high definition Divx and XviD videos without some trickery. I figured out that they play a lot better if I watch the video from an external firewire drive rather than the internal drive so it sounds like the fault is in the laptop harddrive.
* Not all Gentoo packages compile on it.
* Firefox is a memory hog I don't want to deal with so I don't. Safari is a great replacement though I haven't been able to get ad-blocking programs to work.
* Many Gentoo packages compile on it. Gentoo on OSX is decent. There's also Fink and DarwinPorts, but I'm a Gentooer.
* It came with my bitch language, Python, as well as Java and GCC.
* Civilization 3 plays twice as fast on this machine as it did on my 2GHz P4 when I had Windows installed a few years ago.
* iTunes is way better than gtkpod.
* I can run Quicktime, WMP, RealPlayer, Cisco VPN client, Remote Desktop Connection, Maya PLE, and Macromedia Studio. And I do.
* Apple provides X11 for OSX so I can run GIMP and Inkscape.
* NeoOffice == OpenOffice for OSX, which is nice.
Oh, another downside: With all this stuff simply working (Have you seen how installation works on a Mac? It's almost disgusting!) I feel like I'm getting stupider every day. At the same time I can still pull up my Bash prompt and geek out whenever I want, which is pretty often. It's basically all the functionality I got out of Linux and still being leaps and bounds better than Windows.
I don't know if many are familiar with it, but I could never use Windows for long without replacing the shell with Litestep. I nearly require a clean interface to get anything done. OSX is where that action is at.