OK, it’s now been about a week since my first installation of Mac OS X 10.5 (aka Leopard), and after the first round of notes, I have a few other observations to throw out there.

• I get the distinct feeling that my MacBook Pro’s battery life is a bit shorter under Leopard than it was under Tiger — there are a bunch of posts to various Mac-related websites saying the same thing, so there appears to be power in numbers here, and not just a funny feeling on my part. That sucks; over the next few weeks, I’ll get the sense of whether it’s a real issue or not.
• The new version of Mail.app seems to have some sort of seriously screwed-up issue with my IMAP account configuration. Last night, my MacBook Pro sounded like an airline tooling up to take off, and I discovered that Mail.app was re-downloading nearly 3 Gb of mail that it already had in its cache, for reasons that I can’t even begin to fathom. Right now, I’m sitting here five minutes after I asked Mail.app to quit, and can still see four processes in the program’s Activity window that don’t seem to want to give way; clicking the stop icon on one of them just led to a spinning rainbow beach ball of doom, and I’ll have to force-quit the app entirely. All in all, a functioning Mail.app is a must-have for me, and if I can’t figure this one out, it’ll mean either moving to another mail application entirely, or downgrading to Tiger.
• Speaking of unstable, I’ve now had to force-quit Finder itself a half-dozen times under Leopard. The first two times, I connected to shared drives, and then noticed that the drives didn’t appear in the “Shared” section of Finder’s sidebar, despite me clearly being connected to them; that meant that in order to disconnect from the shares, I had to manually issue the unmount commands from the terminal prompt. Force-quitting Finder restored their listings in the sidebar, and all related functionality. Then, I noticed that one time, I created a new Spotlight search template and checked the box to have it saved to the sidebar but it didn’t show up; again, force-quitting the Finder fixed the issue. Both of these issues have recurred a few more times, which is pretty annoying. And notably, all the other functionality of the Finder has remained intact during these periods — it’s not like I needed to force-quit the Finder to restore all functionality, just the “Shared” and “Search For” lists in the sidebar.
• And speaking of Spotlight, Leopard’s new implementation might be better in a lot of ways, but it’s pretty broken in a bunch of others. The biggest problem I’ve run into is that Leopard’s Spotlight seems to operate with a bunch of internal, undocumented filters in place that hide whole classes of potential search results, something that others have also noticed. As an example, if you use the basic Spotlight search interface to look for a file that lives in any of the system-type directories (e.g., the system-wide or user-specific Preferences folders), you won’t find the file — those are now excluded from the general search results. The only way to actually get Spotlight to show them to you is to use the advanced interface, enable the “System Files” choice in the criteria drop-down, and set it to “include” — and this setting only applies to your current search. You can create a template for this that you can then access for future searches, but you can’t ever access that template through the basic, upper-right-hand-of-your-screen search interface; instead, it’s a two-step process where you have to manually start your search from the template and then choose it (rather than “This Mac”) from the “Search:” options that are displayed at the top of your search result pane. This is just inane.
• Finally, Leopard lost all knowledge of the printers that I had set up on all my machines… and given that all three machines are in a work environment with multiple printers and setups, this was quite a pain in the ass.