I finally upgraded my primary Mac to Tiger, because the 10.4.2 release seems to have stomped most of the bugs I cared about (or the bugs I cared most about; works either way). There are some things that I don’t consider improvements, like the Mail.app UI, but so far only one change has actually annoyed me: emacs broke.
More precisely, the vt102 emulation in Terminal.app changed just a tiny bit, forcing me to remove the stty -tabs line that’s been in my Unix dotfiles for the past 18 years. It’s a pity that I got rid of my honest-to-gosh DEC VT102 about ten years ago, or I could file a truly outraged bug report with Apple.
Admittedly, the fact that this is the first time they’ve done something that broke my dotfiles is actually a pretty good sign.