So I got my Leopard disk yesterday, and I decided to go right to install it on my 1.33 Ghz G4 iBook with 1.5 GBs of RAM. I booted up from the CD and did a partition, cutting my drive directly in half, so I could still use Tiger. Overall, I am pretty pleased. It now dual boots Tiger and Leopard. I haven't noticed much of a change in speed, but it is barely slower. However, it can run much more modern software. It does use more CPU power, which is believable, but many people say that Leopard is a bad upgrade for a G4, and that is not true. It takes slightly longer to boot up, but still faster than a lot of PCs I've seen. Everything worked out of the box. While installing updates, my trackpad stopped working, and the prefpane appeared in the prefpanes folder, but not in System Preferences. Upon reboot, everything worked. The system does heat up faster, but that's not really a problem. I think Leopard is a pretty good upgrade for the G4, and it can still run relatively modern software! I'm pretty exited to finally get Leopard running on the iBook. Overall installation didn't take too long, I didn't time it, but I think it was around 1 hour.