It's not really a comparison between Linux and OS X, because my iBook 1.33GHz is much faster than the 700MHz PIII I run Debian GNU/Linux on, and since I installed Screen Spanning Doctor the iBook on 1600x1200 also outperforms my Linux hardware at that point. So why do I even bother with Linux on an old PIII when I've got a faster iBook?

My Linux box has a TV-card, my iBook hasn't. Maybe it's a plan to hook the linux box up to the other 19" so I can use the iBook and watch TV at the same time. Best of both worlds...

But on the Linux box I also use KDE with multiple desktops and OS X doesn't have that out of the box. I got as far as changing the windowmanager of Apple's X11 to Enlightenment, but that didn't really walk with the dual head setup and confuses Exposure and stuff like that. It's nice that it's all possible, like a PPC Linux Live CD, but it just doesn't cut it as a serious desktop environment. So the main thing I miss in OS X is multiple desktops. And the Linux box is stable in more ways: it's also my server so on multiple desktops multiple applications are open and they stay open until I have compiled another kernel, which leads to another environment than a laptop that switches between dual- and mono-head, goes offline, roams on several networks and doesn't have private keys stored on it. Even a 'fink install kde' won't change that...