Well. one week into Leopard and I've had it. I've gone back to Tiger. It wasn't as bad as going from XP to Vista but it did force me to retreat anyway. By the way, I did a clean install. I think most of the problems centered around two things... 1. Time Machine 2. Permissions Time Machine BOGGED DOWN my MBP like converting a movie file would on Windows 98. UNACCEPTABLE! If I was viewing a file in QuickTime and TM came on, the movie went into slow motion and the entire system seemed taxed. Plus, with VMware Fusion running, it would lock up Fusion and I'd have to force a shut down and one time I had to push the power button to get the system unstuck. I tried to install several drivers and updates and it appears that Apple has implemented some new security measures that prevents programs from, well, working. I downloaded a Xerox ColorSeries driver and Leo wouldn't let it install. I downloaded the update F for Sims 2 and it too wouldn't get past Go. Oddly, the first thing I noticed when switching back is that Tiger is brighter and easier on the eyes. The text is larger and the default icons are brighter. I didn't notice that when upgrading. Plus the Tiger toolbar is better. No doubt. Sorta depressing in a way. I waited almost six months from purchase (of my MBP) to get Leopard and will probably wait another six before I upgrade again.