I finally got me Mac OS X 10.1, and while I am not a fan of Mac OS X, version 10.1 is significantly better than 10.0. Lots of good stuff in it, much cleaner and more consistent. I still hate the paned file dialogs. It seems slightly easier to navigate overall.
I installed it, and the Dev Tools, on the new PowerBook on a 2GB partition, and on the old PowerBook on the single 12GB drive (so both Mac OS X 10.1 and Mac OS 9.2.1 are on the same partition). I plan on this old PowerBook being my Mac OS X box.
So far, it seems reasonable. I don't like iTunes; SoundJam MP is far better. iTunes is too dumbed down (and dumb). I did get xmms (along with gnome, XFree86, etc.) installed (using fink, a port of apt-get/dselect), but it doesn't work well yet. I need an MP3 player on this box. I spent an hour or so figuring out how to get lookupd and NetInfo configured so I could override DNS, which I would call a huge waste of time except for that now I understand NetInfo a bit better.
I can't do USB Printer Sharing with it, which is a royal pain. Also, this computer has hardware DVD decoding, and the only Apple DVD player for Mac OS X is for software decoding. Fooey!
So I can use it for development and for file serving and for MP3 playing and for general playing around
It's still much too far away for me to use as a replacement for Mac OS 9.