I like the flat screen. I can deal with the transparency. The little dock bar at the bottom is kinda cute. The GUI is screen-lickingly pretty.
What frustrates me is knowing that there's a perfectly good Unix system underneath (even down to the XFree86-Darwin icon in the dock) without being able to run X applications over an X tunnel. At least, I can't seem to figure out how to do it. I can get a rootless X working, and I have X forwarded through the firewall securely over SSH for Linux boxes in lots of places, but here in the computer lab at OSCON, I can't get it to work.
Maybe I'll have to stay close to people with Linux laptops. Surely some of them owe me beers... :)