I just wanted to tell my experience with Leopard on my iBook 1,33 ghz G4, with 1gb ram and 60gb hdd. First, I made a clean installation, and it took about two hours. And another hour for Spotlight indexing after that. Well, there are plenty reviews of Leopard so i'll focus on iBook specifik stuff. Most animations run smooth, which actually surprised me. Coverflow runs smooth, but it does take som time to get the actual icons to show. On a sidenote Coverflow in iTunes have improved vastly, well actually iTunes performance as a whole seems better. Expose stutters a bit, which is a little weird as that ran smooth in Tiger. Maybe they'll fix it later, and if not its not all that important. Spaces is fast, nothing to complain about there. Finder is much more responsive. The dock stutters a little if magnification is turned on, the mirror thing works so-so, you do see some stuttering if you move a window around quickly, the stuttering goes away if you hide the dock. Timemachine works well, some stuttering. Frontrow animation is flawless, though I have been experiencing a problem with my ripped futurama episodes, it plays the video way faster then meant to. Both iTunes and QT plays them correctly. Safari is noticeably faster. Quicklook is mainly unuseable with video, works fine with pdfs and images. Spotlight is somewhat faster, but I think I'm going to use Quicksilver as a launcher instead. Well that was my initial thoughts on the subject, I'll report back if I find more of interest. Update: Using the 2d dock helps the Expose stuttering. But I think I actually like the depth the 3d dock brings, so mostly I would like a way to just disable the mirror effect on the 3d dock.