I guess the people who have fallen in love with MacOS X use their computers for different reasons than me. And maybe they have better hardware.
Hardware: I have a 600Mhz iBook, and MacOS X is often slow. The screen real-estate is pretty inadequate. Remapping capslock to control introduces annoying bugs (sticky control) because the laptop uses an ADB keyboard that is easily confused. I got an Apple Pro Mouse. It's cute, but the cord is barely enough to go from the USB port on the left of the laptop to the right side of the laptop (I'm right handed).
Software: I use Terminal.app (which sucks) and Mozilla (which sucks less, slowly). I dont use iTunes; though I like the interface, it's rarely convenient to hook headphones up to the laptop, and the built-in speakers are a sad joke. And all my MP3s are on a samba share that OS X can't consistently connect to. I ssh to my desktop and use mpg123 when I want to listen to music. I tried iPhoto, but the laptop is too small and slow to view even moderately sized images. And using the trackpad is painful. Oh yeah, there is no consistent way to cycle through windows on your screen; the default cycling switches applications, and each application is free to implement its own window cycling scheme. Some, like Mozilla, don't seem to bother, necessitating using the trackpad to swap between browser windows.
Some applications ignore the very useful "esc means cancel" option for dialog boxes. Argh.
It has changed how I use computers. I haven't sat at my desktop in several weeks, but I also haven't done any serious work at home in several weeks either. The wireless is nice, but I'm thinking I should have gone with a cheaper, faster Intel-based laptop.
The iBook and MacOS X just haven't increased my quality of computing life enough to make me rave.