I’ve got Tiger on my laptop, and my initial impressions are mixed. There are some very cool new features (spotlight and the dashboard widgets) but very little else that I’ve noticed different. On the negative side, the ogg/quicktime plugin that I have been using in iTunes stopped working, and any attempt to play an .ogg file causes iTunes to crash. This is annoying, since 75% of my music is in .ogg format. I’m using the plugin from qtcomponents.sf.net, and I imagine that a fix will be forthcoming eventually, but for the moment it is deeply irritating.
I imagine it will grow on me, and I’ll find other things that are neat. After all, there are 216 new features.